Thanks ladies.
I hope to stay friends with her. I think Im going to see how things go for the time being.

After talking with DH last night, I think I feel like them breaking up means we are losing more of our niece (carly). I kinda feel like we've already lost her once. We went to her farewell. we grieved for her. Now with brother and sil breaking up, I really feel like we are losing another piece of Carly. I feel like our niece is fading away slowly. In my mind, if they stayed together had more babies, and lived a happy life together, than Carly's memory lives on. Now I kind of feel like they are both going to go off and find new partnes, and hopefully have families. And then maybe, Carly's memory will be lessened. I have a strange mind, and I know Im being silly, and their break-up is definately not about me either.
but then I am worried that I only want to stay friends with her, so that I can try and keep my weird way of thinking happy.