Why is she acting weird around me?

I think she might like you, but she's acting kind of immature about it. Her friends know that she likes you and that's why they're giggling. That's what some of my more immature friends do when I walk near or am talking to the guy I like, but then again, I'm in high school. I think she has some silly crush on you. You should just keep acting normal around her and maybe she'll get more comfortable around you.