Take your time. She's going to have to learn to trust you. Just sit with her. Hold out your hand. Talk gently to her. Try to hand feed. Go very slow. Give her a few toys and try to entice her. Hmm.. I wonder if a laser light would get her attention. The cats at the rescue love that! Speaking of which, check and see if they have an animal rescue around your area if you don't feel you're going to keep her. Good luck! It's going to be hard and time consuming but don't give up on her!