Am In the right to feel this way?

My sister is giving up full custody of her son to be an escort and sell drugs, clearly she hangs around awful people who are super dangerous and she's been doing this for years. She was in Colorado like me, but she moved back to Cali like 2 weeks ago. She's giving full custody to my mom and dad and they've asked me to move in with them to basically raise him, because my sister will be living and staying in California but he's coming back to Colorado. I already have a toddler and he's toddler and they are both bratty as it is. I'm not happy about this, she's coming to visit for Thanksgiving. I will be watching her son everyday for 8 hours. I'm basically going to be his mom. is it messed up that I literally never care about seeing her again? because I don't. She's stupid and Im just like who do you think you are. when you're a parent you don't get to just pull shit like this. I feel too many people in my family coddle her hence her giving up her own son. everyones else is welcoming. I don't want to see the bitch again.