Re: It hurts me that my friend doesn't trust me
If you haven't done anything to her, and the reason she doesn't trust you is because of HER past, I don't think there is anything you can do to earn her trust, other than give it time. It's her issue, not yours. You can't cure her issues, SHE is the one who needs to work on this, not you.
I would say all you can do at this point is give her time, be there and continue to NOT do anything to against her.
If she is willing to talk about her past with you, talk to her about it and listen to her. That's the most important piece in gaining trust - showing you care by listening.