Whatever. I don’t need to know your situation. If you cherish your family, then TRY to get along with them. If you can’t get along with your parents, at least try to get along with your sister. Based on your answer, it seems like you have times where you did get along with her, then something happened that made you don’t. Also based on your answer, it seems like your sister has did her part and you’re the one who don’t. Do something if you want to fix that broken relationship.

Don’t wait until they’re gone. You can feel sorry all you want in their grave but nothing can be done when they’re gone. You don’t need for them to be gone to realize that do you?