Okay, I promise not to be dramatic here, but I just need to tell you this. If you have a sister, and you don't really get along with her for one reason or another, could you call her anyway and tell her you love her?
I just finished my umpteenth lecture to my girls about getting along. It's like they hate each other, but it only bothers my older one and she cries when the younger one is mean to her. I told them that the day will come when they WANT a sister but it'll be too late.
Not a day goes by ... and listen, because I'm serious about this. Not a DAY goes by where I don't think about picking up the phone and calling my sister with a question, or a joke, or a recipe, or an opinion, or just to hear her talk. But I can't, because she isn't here any more. I can't even impress on them how important it is to value what you have when you have it ... because you never know when you won't have it anymore.