What to do about this girl?

I recently started working in a new job in a new town and I don't know anyone here. I was put on a 2 month project with a guy and another girl. We all got on really well. I viewed them as friends and I went out a few times with them for after work drinks and just with the girl also a few times when we had worked late. The girl kept sending me chatty emails but I just thought it was friendly stuff. Anyway, it eventually turns out she 'likes me' and thinks I was leading her on, when I wasn't, I thought we were just colleagues and socialised with her because I was new to the town. Although I'm not in a relationship I really don't feel that way about her at all. I told her I just wanted to be friends but she didn't listen. She keeps telling me how lonely she is and how she wanted to get married and have children but she doesn't think she ever will. I kind of feel I'm being put on some kind of guilt trip. I suddenly feel really uncomfortable working with her and don't know what to do.