I think there is no problem with still being friends with this girl, it is obvious that you both get on. I don't have a lot of female friends, but one in particular wasn't interested in me romantically (even though she said I was good looking), but that did not stop me from being friends with her at all, she has always been nice to me. And no, I'm not holding out for hope, that can only be detrimental, if it happens, it happens.