EDIT: I posted an update here, which is unfortunately not super great. https://www.reddit.com/user/pls_send_advice_ty/comments/1d97r2v/update_my_30f_sister_26f_wants_to_move_into_my/
Thank you again to everyone who read and responded. I went through every single comment and have been talking about this with other people. I really appreciate everyone for taking the time to read and reply.
tldr: My sister wants to move into my mother's 3-bedroom house to save up for a down payment to move to another state, but she doesn't want me there because she is worried we'll argue. I'm in grad school and visit home during breaks, but she said that she doesn't want to see me there. I feel torn because I want her to move back to save money, but I also feel like I should be allowed to be there. We have been sort of NC since early 2024.
Background: I'm (30F) in grad school and visit my family during school breaks. My sister (26F) has been living with her fiance (31M) in an apartment close to my mother's house. Over the last few years, they have been saving up for a down payment to move to a different state.
In early 2024, my sister and I got into an argument because she and her fiance got engaged while abroad when I was pet sitting for them. I found out through my friends who saw it on my sister's social media. When my sister and her fiance dropped off gifts from their travels, my sister said she was surprised I got them an engagement gift because she heard I was upset about the engagement (presumably through our mother). I said I was upset, but that we didn't need to talk about it. I tried to shut down the conversation twice, but her fiance insisted we talk about it because he said he was excited to bring me gifts, but I wasn't excited about their engagement; and that the engagement was supposed to be about them, but I was making it about my feelings. I said that if they wanted to talk about it, then I wasn't upset about the engagement as much as I was about my relationship with my sister.
Last year, my sister had said that she didn't feel comfortable talking to me anymore because I came off as judgmental and condescending. I told her that I would work on it. She also brought up that when our father left when we were kids, I took it out on her, and that she wanted more boundaries with me. I apologized, and then we didn't talk much after that.
So, when we spoke early this year, I asked what she meant by boundaries. She said that she made her boundaries clear when we last spoke, and that by asking about her boundaries, I was disrespecting them. I told her I thought there might be miscommunication because I wasn't sure what she was referring to, but she said there wasn't any. I asked her to specify what she was referring to, and she said that I knew what she was referring to because I was there. Eventually, she said I was abusive and that when our father left, I told her multiple times that he didn't love her, and that I had deliberately broken her toys when we were little. I told her I wasn't trying to gaslight her, but I really didn't remember. I asked if she had more recent examples, and she said that when I moved home after undergrad, I once asked her to clear her desk off in the evening, but when she was taking too long, I knocked everything off her desk and screamed at her, and kicked her out of the house. She said I kicked her out of the house multiple times and forced her to sleep on the streets, and that I destroyed her bedroom before.
Around this time, her fiance said he expected a considerate person to immediately apologize instead of asking questions, at which point I did apologize. I asked my sister if she still viewed me in the same way as she was describing. Before she responded, they asked if I felt characterized unfairly. I said that it didn't matter whether I felt it was unfair because the focus of the conversation right now was on my sister's feelings, not on me. I asked her if she wanted to spend time with me anymore or if she felt obligated to (because we still had dinners together when I visited). She said she didn't have to answer that question.
The next day, my mother said that my sister called saying that her fiance suggested they move into my mother's house. My mother said no because I still came over for breaks. My sister called her back asking for $42.5k as an engagement gift for the down payment of a house. My mother agreed, on the condition that she didn't move back in with her. After this, I returned to grad school which is several states away. My sister asked me several times through my mother if I could pet sit for her while she was traveling. I said no. Recently, she quit her job at her fiance's workplace, and has been asking to move back in. My mother asked if my sister still expected the $42.5k after moving back in. My sister said that because our mother already promised her the money, she couldn't take it back. I told my mother that I didn't care if my sister lived there, as long as I could still visit. My mother called me today to tell me that when she told my sister that I wanted to still visit for breaks, my sister said if I returned, I was wasting her a year on rent because she didn’t want me there. My sister also told my mother to tell me to stay at an airbnb when I visited home, but I can't afford to pay rent and an airbnb on my current stipend.
At this point, my mother and aunt told me to let them live there and wait 1-2 years before visiting home. I feel like I'm going crazy and I'm really struggling to understand where my sister is coming from. My mother also wants my sister to move home because she's worried about her, which I understand. But I feel stressed about this situation and have no idea what I should do or even can do. I'm looking for input on whether there is something logical in my sister's behavior that I'm missing, and whether I should agree to not visit home for a year or two, while she lives at our mother's house.
Edit: Thank you everyone for your comments and thoughts. I need to head to bed because I have an early morning, but I'll try to respond more when I have time. I feel a lot less crazy after reading through these, so thank you. A lot of people brought up that I needed to stand up for myself more, which is something a lot of my friends have said too. My mother said she was going to talk to my sister and then get back to me, so I'll hear her out first and see where to go from there. Thank you again for your time and energy in responding. I really appreciate it.
Edit 2: I didn't expect this to get so many comments. I can't respond individually to everyone right now, but I want to clarify and answer some questions people brought up:
Around the time my sister and her fiance started dating, we got into an argument because I said it was inappropriate for him to be her doctor and that he asked her out during an appointment. Before then, my sister and I used to talk several times a week, but she stopped calling and my calls/texts weren't going through. I suspected she blocked me but she kept saying she had phone issues. For the last few years, I have only been able to talk directly with my sister in person. All calls and texts went through someone else. Last year, she finally admitted to blocking me and said she wanted "more boundaries", but didn't elaborate more than that. In this same conversation, she said that when our father left (I was ~8 and she was ~4), I took it out on her. She did not give examples. I apologized and she thanked me for being receptive. The rest (and majority) of this conversation was about how I came off as judgmental and condescending. When I asked for examples, she couldn't remember any, but I said I would try to be more mindful of my words and tone.
Fast forward to this year. My sister asked me (through her fiance) to fly home from school to pet sit for 3 weeks. I'm done with classes and am working full time on my thesis, and my work said I could temporarily work remote, so I was able to go. My sister and her fiance got engaged while abroad. My sister has a significant following on tiktok to the point of getting sponsorships, so when she posted about the engagement, my friends saw it first and told me. She wasn't planning to tell any of our family members. I wasn't upset that they got engaged. I was upset that they didn't tell me. I had been feeling distant from my sister for several years now but wanted to give her space. I was upset that in this time, she still asked me for money or to pet sit, and I always said yes, but it seemed like she wanted things from me rather than a relationship.
When my sister and her fiance dropped off gifts from their travels, my mother asked me not to argue with her. She said that she asked the same of my sister. This is why I tried to shut down the conversation twice when they brought up that I was upset about the engagement, but her fiance kept insisting we talk about it, so I said that it wasn't that I was upset about the engagement itself – I was upset about my relationship with my sister. This is when I asked her about boundaries. I wanted to know what she wanted from our relationship and what our interactions would look like, given we were no longer close but she was still asking for favors. She said she made her boundaries clear last year. I disagreed and said I think there was miscommunication because I still wasn't sure what her boundaries were. This was when she said I was abusive and gave examples. I was mostly confused when she mentioned all these things, which is why I was asking questions. I have never kicked my sister out of the house or destroyed her room, and my mother agrees with me. There were things in what she was saying that didn't make sense to me, like why I would ask her to clear her own desk in her room in the middle of the night, yet get upset that she was taking too long, and kick her out of the house. Or how she was able to sleep on the streets without anyone noticing, including our family pets, who would have made a lot of noise. This was when her fiance said he expected a considerate person to apologize instead of asking questions. I apologized then, which I now regret, because I think by apologizing, I implied that I did the things she described.
When her fiance asked me if I felt characterized unfairly, I did feel that it was unfair but I responded in the way I did because if I said yes, I think they would have accused me of gas lighting them. My sister had already brought up earlier in the conversation that I was blocking out memories, so I felt like if I gave a yes or no answer, I would still be accused as being abusive. I thought by shifting the conversation back to my sister's feelings, we could focus on what she wanted from our relationship, but the conversation didn't turn out that way.
I didn't write this in the original post, but after they left, I asked her fiance if I could send a letter to my sister through him because she had me blocked and didn't want direct contact. In the text, I thanked them for coming over and having this conversation because it was difficult for everyone involved. I said that whenever I tried to explain my perspective, it unintentionally came off as an invalidation of hers, which is not my intent. I said that I had spoken to our mother, who agrees with me that what she is describing from adulthood never happened. I apologized again for my behavior in elementary school, when I told her our father didn't love her and when I had broken her toys. Her fiance texted back that they didn't want further contact from me. The following day, my mother said that my sister had asked for cash as an engagement gift. My sister had originally asked for $100k, but my mother talked her down to $42.5k. Since then, I have not tried to reach out to my sister at all. She has still asked me multiple times (through our mother) to fly back to pet sit. I have said no every time.
This leads to the present day situation. I'm supposed to fly home soon and the original agreement was that my sister would take the $42.5k and not move into my mother's house with her fiance. But she said that since she quit her job, she needed to save up money faster and wants to move in the next 2 weeks. (She quit because she said it was too stressful. She had been working at her fiance's place for about a month. Before that, she was only doing social media sponsorships and getting $1.3k a month from my mother as financial support.) My sister is now trying to move in and take the $42.5k, but she says I'm not allowed to be there. I know all of this sounds insane, but my sister wasn't like this at all until recently. Everything she's saying and doing right now feels very uncharacteristic of her. We were close up until a few years ago, and everything she is now bringing up feels like it's coming out of nowhere. I know a lot of people have been saying to go NC, but my mother and I are worried about her because she's lost all her friends (which is why she always asks me to fly in to pet sit).
And to everyone asking about my sister and her fiance's finances: I did ask about that. My mother said that my sister said she doesn't know how much money he has saved up, but they had been saving up for the last few years. I don't know how much money he makes, but based on his job, the bare minimum should be $100k/year. However, I know he has student loans, so I don't know how much he's paying back.
A few people also asked whether my mother financially supported me in the past. She has, yes, when I was in undergrad. My tuition/dorm was mostly covered with scholarships, but she covered whatever was left using a parent plus loan, which I agreed to pay back after grad school. She hasn't financially supported me since I was 20. I moved back home after undergrad for 1 year to work full time and save money. After that, I moved out of state and have been financially independent since.