What was your relationship with this girl? Why was she doing this with you?
If it was just a hook up, chances are she was doing it not so much to share her deep seated, longstanding feelings of closeness and love for you, but rather to please you in the attempt that you'll pay attention to her and stay with her. This is not the stuff that brings out the best in people's sexual performance! And, if this is the case, then she's probably pretty inexperienced at what to do. The learning process (in most things, not just sexual ones) occurs best when there's a good relationship between student and teacher, where the basis is one of mutual respect. Not horniness (yours) and neediness (hers).
I think there's a reason why all the old folks say it's best to wait.