my younger sister is SO annoying.

hii first post in a while, ive been busy.

but oh my god, its been getting worse every week. my parents continue to favor my young sister who's 10 all. the. freaking. time. I keep telling them what they should do so its more equal but they think they're doing nothing wrong (even w evidence). My parents always say "we treat both of you equally" until my sister gets out of things because shes younger, and i should know better because im older. It's to the point i dont even get accommodated for my disability anymore. Do y'all have any ideas of how i could change their mind? Or at least get my sister to listen to me sometimes because one day she's gonna get bullied a lot. Yes, ive spoken to my therapist about it and she hasn't helped.