(Please Help) Should I Be Worried? Need Advice Please...?

If she says she's not interested in him then just trust her and that will probably make her like you more if she knows you can trust her and she can trust you :) also i wouldnt ask about him anymore because you might cause her to pull away from you. So i would just lay off for a while but if you get to the point where you just HAVE to ask about it, tell her your only asking because you care about her and you dont wanna lose her. Honesty is the best policy :) good luck!! :]