AITAH for lowkey hating my grandma with alzheimers?

Sounds bad I know.

I (18f) dislike my grandma (70 something) for several reasons, the first one being the fact that she was a really bad mother. She mistreated my mom her entire childhood, made her start working early, made her basically become a teen parent to my aunt who's 12 years younger...my mom is the most important person in the world to me, so naturally I was very angry after learning this.

"But you weren't even born yet, shouldn't that stay in the past?" maybe, but since she has alzheimers, she's been living with us for a while now. That woman treated my mom like shit her entire life, and now she's taking basically all of her free time despite all that.

Another reason being the fact that she hates cats. I have 3 cats, and she's genuinely tried to hurt them before, but I can't say anything because "she doesn't know what she's doing" (she absolutely did this sort of thing before developing alzheimers)

We don't go on vacations cause someone has to stay behind, we don't let the cats inside after a certain time of the day cause she might hurt them (they stay in the patio, don't worry), all because of some old hag who never did anything to deserve my mom's time and care but gets it anyway.

I genuinely wouldn't care if she died, I would only be worried about my mom's feelings cause that's still her mother afterall, am I being too harsh?