I know how you feel, but I am here to reassure you. My dd was a chunky thing. Ok she was fat at your dd's age and beyond. My dd was very active, but I have some pictures of her at cheer competitions that made me cringe. Seriously she was that large child that people felt sorry for (your child isn't that large just talking about mine).
Bottom line is dd loved to eat and still does. I never focused on it, just tried to make healthier choices for her when I was cooking. Fast forward to age 13. She is very solid as she is an athlete (competitive trampoline and tumbling). She is about 5'4" and 115 lbs. I was 5'6" and 103 when I graduated at 18. However she wears a size 1/2 pants and let's just say no one ever calls her fat. She has a beautiful body. She is likely about as big as she will get (I'm hoping for another inch for her). She has stayed this same weight for several years. Child still mows down on food, but it has worked for her. Now to keep the boys away as she doesn't look 13
It will be fine. Don't worry about it, and just help her make better decisions for herself even if she doesn't know she is doing it. I used to worry so much, but it is fine for dd. You know if your child is overweight by looking. I mean honestly I would think if I told someone my 13yo weighed 115 they would think her fat if they had never seen her. Don't compare numbers.