The kid is in high school, which does not matter at all. Once you go to college its a whole different game and the couple will most likely break up when they go to different schools. If she is hot then she will find some dude with bigger and better things, who knows?! You can go around and try to fuck all the hot taken ladies but some day one boyfriend is going to beat the shit out of you. Seen it, and it is not pretty.
Goodluck with your whole dilemma, if it was me I would probably try to be good friends but not necessarily in the "friend zone." Soon the two break up, you go to prom with her, make a move and FUCK, hangout over the summer, go to college and you will be iron chef of pounding "vaj." This is risky however, because you don't want to get attached especially when you go away to school.