Hmm... that's a toughy. lol

Well I think that it is pretty obvious that she likes you. Hopefully you have realized that too, which I'm sure you have. Anyway, maybe she always says that she doesn't want to talk about it because she is afraid. You say that she has never had a boyfriend before and that you have had girlfriends in the past. Also that you are 16 and she is only 14. I can tell you right now, that as a 14 year old girl which I am, I get pretty scared at the idea of dating the the guy I like right now. And he too is 16 lol. Well 17 almost but that is besides the point. Maybe she is just a little scared of being with someone older or with someone who has more experience with dating. Girls get can get really worked up about little things like these.

I really don't know. I tried to give it my best shot. Maybe just give her some time without the constant questions. Let her warm up to you a little bit more and feel more comfortable around you. I really don't know what else you could do. Maybe someone else could help you out better than I could.
Good luck!