I have to admit, that would throw me off too.She's been saying weird things, I don't know. Like "good boy" when I first get my dick in.
If you really don't click sexually (and I'm not just saying, because she says "good boy" or "thank you" -- you sound really unsatisfied and incompatible with her), I would probably just dump her and move on. Life's too short, and that's too huge a part of the relationship. And she is not going to like you after however long it takes to "mold" her to your liking, if that even works. "I don't think we have any physical chemistry" is valid. You already were pushing it trying to get her off the "saving myself for marriage" thing...
I wouldn't pay much attention to the people saying what she's doing is hot and you're lucky. You don't sound lucky, and you don't sound happy. There is such a thing as bad sex, GAF, and even such a thing as girls who are weird about sex, that you don't find out about until you're in the relationship. I've been there. I'm glad not to be there anymore. My current gf is amazing, my last one was awful and weird. The giggling was a sign of her own discomfort with sex in general. Hell with that, I say.
And being honest, do you really expect to be with her for life, meaning you would be the only person she ever sleeps with? If not, maybe let her get her experiences and figure shit out elsewhere.