Do you need to lose weight if you are a 12 year old girl and you weigh 11 stone?

No!!!! Enjoy yourself while you are young. You will grow a lot taller and as you grow you will lose some of the weight. You should have a healthy diet as you are growing up. You are still young and a lot more time to grow. no but u should try not to put on any more weight and make sure you do lots of exercise.