Does this girl like me or not?

There's a girl who I really like.I know you've seen these before.I don't know if she likes me back.I've told one of my mates and ever since I did he has been flirting with her on purpose and I think she likes him, not me.She always laughs at my jokes,looks at me nervously,and practically shows off when i'm around.Once I thought she got so nervous of me because I was teasing her and pestering her so much in a way, that she blurted out that shes "Killed" someone before!And also she Looks at me 99.99999% of the time.She stares at me smiling and daydreams a lot but the girl I like is really quiet, and creepy at the same time.She has friends, but doesn't exactly hang out in the "Popular group" and hangs out with girls who are younger than her about 99.9% of the time as well.So that's why I don't want anyone else to know about my crush on her, because they would think that I'm mental!She is crazy time to time as well especially when i'm in the room, She can rugby tackle boys to the floor!Shes so much fun especially towards me, and what makes me so aware of that I think she might like me, is that her "friends" tease her about me and stuff and show her up whenever i'm in the room!Does she like me?