I agree with day walker, if she was looking for a relationship she def. would have remembered to mark her calendar and showed up, but that doesn't mean much, she may not be looking now, but maybe you two will become friends and that may turn into more. Even if you find out she has a bf now, that can change. I'm not saying try to break her up with her boyfriend, but if you find out she does have one or that she isn't interested right now in having a bf, you can still keep her their as a friend for now, and maybe you'll become a bf option later on...you're gonna be at school with the girl for a while. Just look good for lunch, and I agree that you shouldn't pay for her right now, cause that might be too forward.
Chris