Wow, this girl sounds a lot like me! It is kind of nice to know I'm not the only one who feels that way. Anyway, I agree that she is being very clear and honest with you, which is a good sign. If she didn't care about you, I doubt she'd bother to try and explain the way she feels, as I'm sure it's not easy for her to talk about and that she knew being upfront could cause problems between you two.
I also agree that it is definitely possible to change someone like this's mind. I almost threw up the first time the guy I've been seeing referred to himself as my boyfriend, and we have broken up and gotten back together several times over this exact issue. The last time he finally agreed that we would just see each other casually and not be in a relationship and things have been going smoothly ever since. Ironically, not too long after that, I finally realized that I like him a lot better than any of the other options I was so afraid of missing out on, so I told him I wasn't interested in dating other people anymore. By that point he had resigned himself to us not being committed and started dating other people himself, so who knows what will happen.
Anyway, sorry to ramble on about my situation. My point is that even the most commitment-averse women can come around, provided you are willing to be patient, let things develop slowly, and not pressure her to move faster. Even though the stereotype is that all women are eager to get into relationships, some of us genuinely like being single, or at least need to get to know someone for a long time before we feel comfortable committing. If you really like this girl and are ok with not being super serious right now, I would suggest giving it some time without bringing up commitment and just see what happens. You sound like a great guy, and hopefully she will realize she's lucky to have you...even really dense girls like me are capable of that epiphany, though I hope it doesn't take her quite as long as it took me.
Good luck!
