Call her and ask her if the two of you could get together for coffee or lunch and to talk. Pick a place that has a quiet atmosphere away from mutual friends. Suggest the place you have in mind and that you both meet there.
Nothing is going to take the place of a face to face discussion to really know how she feels. Remind her of her statement about being better friends and tell her that is what you want also. Catch up on what is happening with her and keep it on a non pressure level. The fact that you take the initiative says volumns about how you feel toward her. I'm sure that you will get the answers you need, one way or the other.
