Should I kick my sister out of my apartment?

I (23 F) have been living with my boyfriend (26 M) and my sister (21 F) for over a year now. At first everything way amazing, the three of us always went out together and watched movies together. We played video games and invited people over a lot. Her and I even worked together and we got extremely close, until she quit.

At the time I was working two jobs and going to school so I wasn’t home as much. When I did have free time I tried my best dividing time between my boyfriend and family (including my sister). She had no interest and began becoming obsessed with finding a boyfriend.

She stopped cleaning up around the apartment and her cat started spraying everywhere. She would constantly go out or stay home and drink. Anytime I tired too talk to her or do something with her she shrugged me off. I could tell she was depressed so I started cleaning up after her and gave her the space she wanted. My boyfriend and I even stopped acting like a couple around her so she could see us as friends again. I still tried to communicate with her but then she started getting snappy and rude with me. She had always had an attitude but even when I was being kind she was rude. I just ignored it until she started doing it to my boyfriend.

He didn’t like that I would clean up after her and take her rude comments so he would tell her to clean (nicely) and she snapped at him. We had a talk and she opened up about her depression but she never changed.

It’s been months since we had that talk and now she’s getting worse. She’s spending the night with random people and doesn’t even let me know, when I ask her she gets mad at me for being in her business when I am just worried. She will only clean her room and if she or her cat makes a mess outside of her room she doesn’t clean it up. She doesn’t even throw the trash in her restroom she hides it in the towel closet.

I talked to my older sister about it and apparently my little sister talks crap about me and my boyfriend behind our backs. My older sister and my mom thinks she’s jealous of our relationship but I’m not sure if there is something else. I’m tired of being nice to her and I’m trying to be understanding but this is too much. I feel guilty for wanting to tell her to find another place to live, I know she is feeling heavy right now but I don’t know what to do. I can’t stand her being so harsh to me.

TL;DR
My littler sister is depressed but she takes everything out on me and my boyfriend. I’m thinking about asking her to move but I feel guilty.