To be honest, I don't think a 60/40 ratio is really that bad. It would be different if it was 90% male. But if she is interested in math and science, she will be in college classes with a much higher ratio of boys, and may as well learn to deal with it now. I was very often the ONLY girl in my college classes, mainly because I chose a subject that attracts mostly men. Even in high school, when I took AP chemistry and Calculus, my classes were mostly male. I got used to it, as did the other girls in my classes. If you don't make a big deal of it, neither will she.