I just wanted to toss this out... Seeing someone and paying your respects is not the same thing as setting things right. Setting things right is not required to honor your sister if you wish to. She is the person who wronged you, but she is also the person she was before that, the child you probably played with and the person she is now. I'd suggest doing a bit of soul searching to see if there's any chance you'd have regrets if you didn't say goodbye. Living with regret is tough.

I'm sorry you're going through this. It must be difficult.