This girl sounds immature.
It sounds to me as if she could be confused and really unsure about how to continue or what to do about the situation. She is probably trying to imagine what it would be like to be with you, how things might play out and how a relationship would be viewed from a social standpoint. That, in my opinion, is something that I believe a lot of girls do... They try to imagine how others would perceive the relationship, and that is why she is unsure and not being straight forward, that is why a lot of girls are always unsure and not straight forward when a guy says he has feelings like that. Those are a few reasons some do it anyway I think, and it is immature because in the end what other people think does not matter.
I just think it is different for guys and they are more willing to take chances on things like this and go with the flow. They also don't care so much about social things when interested in a girl. If they are interested a lot will tell you honestly and sometimes quite bluntly. Girls get confused because when you do that, suddenly those images of a potential relationship with you flood their mind and they are unsure which action to take which causes unsurety and anxiousness, as they are emotional creatures. (Unless they have already made up their mind that they want to be with you or to see how things might go and have more of a mature personality) Then they will probably be ecstatic.
Am I an expert on girls?? Certainly not... This is just my opinion on things from past experiences, a bit on analysis of relationship dynamics and female psychology related to this area.