If she rejected me and thinks im ugly why does she stare a t me and try to get my attention any chance she get?

Okay so iv'e known this girl since 8th grade and I used to really like her, so I got my friend to ask her what she thought about me on two way. He called her and asked would she like to go out with me, she said no so I hung up before I could here the reason why. So after 8th grade I go to a different high school as herm but end up getting in trouble and going to a different one. I go to this new high school after i forget all about it and it turns out she goes there. She trys to be nice but I ignor her, now she gets mad and start trying to show off like I used to like her. so here i am later in the yaer with my own new friends and we have one class together. during which she stares, and at lunch she does too. She also accused me of calling her a B***** on facebook which I ddnt. We are also born near each other ( Same Date exactly ). WHAT's The deal.