What is happening here?

There is a girl in my grade, who for a while now has been noticably going out of her way to be near me or see me, and mostly stares from afar. I would normally be cool with this, but I have seen her with a guy that is in one of my cles. I can make out the fact that she probably likes me, but it still is unnerving with the constant "stalking", you could describe it as. Really weird situation!