AITAH for not wanting to watch over my autistic step sister

[u/hellokittyblicky]

So this sounds pretty damn bad. But my dad (58M) asks me (20F) to take care of my autistic step sister (22F) every time I'm with them. I live alone, I moved out 3 months ago but I met my step sister 2 months ago. My dad had been remarried and she's his step daughter now. I help my dad out at his store whenever I'm not working and she's always there. I live 25 miles away from his shop and he asks me to drop her off home every time I leave which makes me take a detour. It takes me around 45 minutes to get home by car and 70 minutes when I drop her home. I've talked to my dad about this and he no longer makes me drive her home. But when I go grocery shopping after, he makes me take her with me and she's very socially unaware so she'll walk in front of random shopping carts as they're moving, peer into random cars, etc. She once peered into a womans car and I pulled her away and then I saw the car wasn't empty. Super awkward because the woman looked visibly confused.

I sympathize with her but she feels like a burden on me. I have a younger brother and I had to take care of him growing up and watch him and now he's making me help out with my older autistic step sister. She constantly talks about how she doesnt have a boyfriend and she doesnt have many friends (she's not the most attractive girl) and she always talks about how she's jealous of me and wants to be me so bad and it irks me whenever any girl says this to me. She talks poorly about other women (ex: "she's dressed like a sl*t!" or "her nose is really big!") but she'll never say anything bad about men she sees on TV and she'll start drooling over them. And I'm a girls girl so it irks me whenever women talk poorly about other women uncalled for. She doesn't know how to handle her dog, she'll keep him on a super tight leash and sometimes she'll grab him really hard and shaking him aggressively. I don't like when she kisses me or grabs my thigh either. Also because she quite literally makes out with her dog tongue and all. She also quite frankly smells really bad because she doesn't wear deodorant and theres always food in between her teeth. She makes messes in my car and starts touching everything in my car.

Anyways I think my step sisters a cool girl but she relies so heavily on the people around her. I'm not her parent I don't want to be watching her whenever I'm around her especially cause she's older. AITAH?