Is it possible for her to know that I'm Facebook stalking her ?

[Gosho]

So as of recently, I've been stalking a girl from my school on Facebook. We don't have any classes together, so I only seer her in the hallway from time to time and we've never talked before. Anywho, after I started looking at her profile more often ( we're not friends on Facebook), I noticed her watching me from a distance on several occasions in school. Also, this one time at the bus stop, we were the only people there and she was trying to keep her distance from me and she and she even caught a different bus than usual. So I've decided that this strange behavior might be because she knows that I'm stalking her on FB. Now, I know the site officially doesn't allow any sorts of apps for tracking people who have visited your profile, but I'm still a bit worried. Am I just overreacting, or is it possible that she really knows ?