I'm going to give my sister some soda.
Why do you want to give her soda?
She will gain weight and not be able to run away fast, maybe she will get cramps.
It's kinda messed up to want to sabotage your sibling like that. Trying to make her sick so she can't run isn't okay.
She's not a child, she's 17 and a pain in my ass, I don't want her here
Even if you find her annoying sometimes you should still love her. You have a relationship with her you won't have with anyone else. It's better to try to keep things amicable as you'll probably be around each other for the rest of your lives.