My Daughter Is 11 Years Old. Has Been Trying To

My daughter is 11 years old. Has been trying to lose weight. She has been exercising. While I have not kept up with calorie count with her, what I do see her eating and exercising, i would think she would have lost some weight. At a doctors visit yesterday, she currently was 160 lbs. She is about 5'3''
Is there something wrong or do I need to get strict in the calorie counting? i hate to be that with her thought.