It's funny

No matter how much we desperately want things to stay the same...they don't.
No matter how much we want out best friend to always be there, it is not possible.
No matter how much we want to get everything out in the open, a lie is always the easiest solution.

All I can say is, love her, hold her and keep trying. Keep being everything she needs you to be. In the end, she is your sister and best friend.