How do I(f22) talk to my roommate(f27) who always plays victim?

So I’ve(f22) been living with my roommate(f27) for 6 months and she’s been giving me issues since she started living here. Nothing has been too bad that I can’t handle because I know the situation is temporary. However, she never cleans, barely takes care of her cat, and blatantly disrespects my property.

The most recent occurrence is that she’s staying somewhere else this week so I’m taking care of her cat, and I noticed that there was cat pee on the side of the litter box. There was cat pee on the wall, the litter mat (which I purchased because she refused), and the floor. I threw out the litter mat and spent a generous amount of time scrubbing the floor, so thankfully the smell is gone now.

Last time I asked her to take better care of her cat and actually clean up after it she blamed her mental health and that she’s “not used to 2 cats shitting in her box” because I also have a cat, then proceeded to tell me she only cleans her cats litter box every week and a half.

I also during the conversation asked her not to touch my brothers stuff (he had recently died and I had all of his belongings), but she again blamed that her life was so terrible and she was dealing with trauma. She then came back to me and asked “Did I do that thing where I don’t acknowledge the problem or apologize?” to which I replied “yes” and she just said “okay.”

Now I feel like I’m stepping on eggshells whenever I’m at home and cleaning the common spaces because I don’t know how to ask her to do her part in being a house mate and cleaning because she always plays victim. Genuinely haven’t even thought of how I’m going to tell her I’m renewing the lease without her because I’m afraid of how she’ll react.

TLDR; Roommate doesn’t do her part in cleaning and plays victim, so I don’t know how to talk to her.