If she hangs around you a lot it might just because she's the most prominent thing in your mind. Think of it like this: if your stare at a coffee mug all day eventually that coffee mug will become the most prominent thing in your head.
Dreaming about someone might not mean you fancy them, it could just mean you want to know them better, or you;ve been spending a lot of time around them recently.
Dreams are very tricksy!