I think you hit the nail on the head there. Being open with others inspires openess in return, being closed means that others will "respect" your privacy even in a close friendship. Try being a little bit more open about yourself in a small way (nothing too heavy right now for obvious reasons) something that might distract her from her own problems. Maybe that way she'll relax and feel closer to you so that she will want to share a bit more with you too.