Is this girl interested? Or just nice?

The thing you should think about is are you interested in her? If you are, then it matters. Since you people aren't even good friends so, she might just be having a lil crush on you, or since she is a nice person, she like you as a person and is being nice and wants to be a better friend. There is no way of telling in such situations (where there are no big hints) till the girl actually confesses. And if you are not interested, what do you care about, she is not even a close friend.