Oh man. you blew that one. When a chick says she's a lesbian thats an opportunity, like spud said!
So she's not even interested in being your freind? Damn! Thats rough.
Lesbians are fun unless they are the butchy penis hating veriety. Which I dont think she falls in that catagory just yet.
If she is as young as you say, I bet she's exploring the "lesbo lifestyle" cause its the thing to do now. All the kids are doing it, right.
Give it some time and she'll be back on our side and wanting the D. if you know what I mean.
So just keep on doing your thing man.
Peace,
Paul Z.