I don't want to have anything to do with my sister
Why not? Can you tell me?
No, you don't have a right to know
It's normal to want to be involved with family. But if they're problematic or toxic you don't have to keep them in your life.
She's extremely bratty. I don't care to forgive her.
Yeah that's the thing, toxic people just want to drag you down to their own level. Stay away and forget her, I know you can do it.