AITA for re reminding my brother’s girlfriend that I own half of the house we live in so she can’t easily get rid of me?

I’m 15F and have been living with my big brother (25) for the last 3 years. Our dad died 3 years ago and our mum abandoned us 7 years ago and is living abroad in Japan with her new family.

I’m very independent and don’t need a lot of attention and generally mind my own business. So I’m not a nuisance or a third wheel, I just need to be left alone.

The house we live in belonged to our dad and he left it equally to both of us.

My brother’s been saying his girlfriend for a couple of years now, she’s not bad and I generally liked her. However, she wants to move in here and they’re talking about getting serious. I talked to my brother about how this would work and he thinks it’s too soon to discuss it and we’ll sort out the details when it’s more serious.

Ok so the other day she came to me and asked about my plans about uni and if I wanted to stay around and told her that yeah I plan to stay home while going to uni. She suggested it might be good for my “growth” to go to a different city and get exposed to new experiences and people, also suggested boarding school for next year. I smelled bs so told her what it’s really about and she mentioned that they’re getting serious and want to start a family soon and I won’t have a place here as they’re growing their family. Talked about importance of nuclear family and all that nonsense.

I asked why is she trying to get rid of me, I’ve done her no harm and she said it isn’t personal and it’s just that their family will deserve to have their own space without relatives living with them. I reminded her that I own half of this “space” so she’s delusional if she thinks she can just get rid of me. She initially said my brother has done enough for me already and it’s fine I do something for him but also said let’s not continue this discussion now.

Later my brother told me I was unnecessarily aggressive and instead should have come to him about what she said. I told him I didn’t approach her she was trying to manipulate me to get rid of me. He thinks she was wrong to do that but I was unnecessarily aggressive and she didn’t mean bad and now I’ve damaged our relationship maybe permanently.

Later he had a fight with her. He hasn’t talked to me since then (4 days now), she also hasn’t been over since then.

AITA for being too aggressive to her?