As crappy as it sounds, if you're a minor and need your parent's permission to change your name, you may have to compromise. What about a unisex first name and masculine middle name? That way you could go by one during school and the other everywhere else. To me, that's more of a compromise. Honestly, I wouldn't (as an adult) be happy with it, but as a minor, I would have jumped at the chance had my mom suggested it. Better than the alternative, I think, and you can always change it again later.