what do I do about my mom

(okay for context.)

My mom isn't the best.

she used to be an alcoholic with anger issues, and she used to hit me and my older sister a lot. She used to/kinda sometimes hit my dad as well and, just like everyone around her, has a story of her lashing out on them, like screaming or trying to fight them, or hell, she's almost attempted to do things that could've killed people.

It's been a lot worse in the past, but now I guess it's okay? I mean, IDK if the word "okay" is right to use. she's not as crazy as she was before. she does have these moments where it's okay to be around her. I know she's?? trying?? I hope she's trying to change.

She doesn't hit my younger brother. well, okay, she threw a glass bottle at my brother once, and he had to get stitches, etc.

And okay, well, if she has these moments, then I guess it's okay to be around her.

But you never know when she'd randomly just lash out again.

Anyway, my parents aren't together because of this.

They haven't gotten a divorce technically, but they're just separated.

We all live with my dad (except for my older sister, who's moved out).

But anyway, my dad has this tendency to feel bad for her because she tends to cry for him. so, occasionally, she comes over, and IDK, it's alright.

I'm not 100% comfortable around her. I kind of just TRY to be nice to her so she doesn't start anything, IDK.

(end of context)

Anyway, my dad, me, and my brothers, etc. all just one day ago moved into a new home after a while of being in hotels, etc.

And well, my mom has been ALRIGHT. I guess to come see the house and help, etc.

She does tend to try to help us with things or buy us food, etc., to ask something about trust.

But yeah, she helped us yesterday with everything with moving in, and she stayed the night because it was late, etc.

Which I get.

However, okay, let me explain the house.

There's like 3 rooms upstairs.

My 2 brothers are up there.

And there are two rooms downstairs.

The big one is my dad's, and the other one is mine. It's pretty small, etc.

I chose it because one of my brothers tends to be up all night playing games, and it's just more private down here.

And my dad kept trying to suggest I go upstairs. He kept saying, "You're the oldest, so you can pick whichever you want."

But it's like he was trying to convince me so badly to get a room upstairs.

And eventually he was just like, "Alright, you can have a small room downstairs."

But this morning, he was like, "I think the rooms upstairs are warmer."

Which, eh, my room was pretty warm actually, so IDK.

I just have this weird nagging feeling that he wants to have me move upstairs so he can let my mom stay in my current room.

Because he'd kind of done this before when he had, like, secretly invited my mom or just let her inside his room, and we all knew it, ngl.

He wasn't exactly slick about it.

But this resulted in A LOT OF stuff, like things.

For example, whenever my mom and dad got into fights, he'd be like, "Oh, don't come over." She'd end up coming over anyway, like mad as hell, coming through the windows or banging on the door.

And that's actually how my brother got hit in the head with a thick glass milk bottle, and his forehead was bleeding, and he had to get stitches, etc.

ALL BECAUSE HE TRIED TO TELL HER TO LEAVE.

After this happened, she didn't even care about what she did.

She blamed it on him because he got loud with her when telling her to leave, like, "Get the fuck out," because he was upset.

Or she just said she didn't remember because she "blacked out."

So that's why, like IDK, I feel like my dad feels bad for her because she has a newborn baby, and she's jobless and living at her mother's house, and she's sad and lonely, blah blah blah.

So he's going to try once again to let her stay here, and I already know it's going to go south.

Because my mother would get too comfortable, and she'd start thinking that she could just boss everyone around, and it's just this whole cycle that's been going on for years.

So yeah, I don't know what to do because I kind of feel bad because of my dad. I asked why.

But at the same time, it's like I know this cycle, I know my mom, and it's just like I can see it already.

Sighs, IDK. I just need advice on what I should do.