WHAT IS ON HER MIND HELP PLZ?

It sounds like she made it clear that she doesn't want to be anything but friends. But it seems like she is really nice and is just trying to make things normal between you which would explain all the smiling and hi's, if you really like her you might just have to wait and see what she starts to feel for you because it sounds like she is kind of confused what she wants, friends, more then friends, friends, back and forth. If you like her enough she's worth waiting for her to decided.