Most Helpful Girl
Just try to encourage the things she does feel good about. Kids start to realize at that age that life isn't always gonna hand them an equal share of the pie in every category. Sometimes its brains, sometimes its looks, sometimes its athletic ability or social skills ... The better a kid feels about their passion, the less the parts they dont' feel good about factor into their overall self confidence. Maybe she could join a club -- band or Girl Scouts or book club, etc.