syrian, you realize its pointless to wear makeup to school, since your not trying to attract anyone at an all-girls school. That reasoning should explain why a Jewish schoolgirl (or anyone not in shidduchim yet) should not wear makeup outside of school either.
Tanchuma Vayishlach Piskah Hey says that makeup and perfume is intended to beautify a wife for her husband, and that beyond that it should be used scarcely if at all.