Is your family eating fresh organic food? You will fill fuller when you eat food that is grown in rich soil and that wasn't grown with pesticides and herbicides, etc. Many of our foods today are totally devoid of the minerals and vitamins our bodies need. Conventional doctors will say that's nonsense, but if you don't already give your daughter a good multivitamin/mineral supplement, please do. You'll be astonished at how much doing that one little thing will have on her health. And don't buy it at the supermarket or Target or drugstore; get it from Whole Foods or Trader Joe's or a co-op in your area. They carry high quality, potent products.
My daughter was like that, too. Hungry all the time. Eat, eat, eat. Never full. Since we've switched over to eating whole organic food and she's been on some supplements, I never hear her say she's hungry unless she's in a growth spurt. She is big for her age--has her father's build--and that will never change; it's predicted she'll be between 5'10 and 6'2 when grown. Yeah. Her dad's 6'2 (I'm 5'3 and one of those who doesn't have to watch weight much). At nine years old she's 5 feet tall and about 127 pounds (we've managed to keep it there for the last year; I'm so proud of her).
She also has Sensory Processing Disorder, which is another issue with eating, and is severely allergic to mosquitoes, so outdoor exercising is a bit of a serious challenge in the summer (in the winter, I have asthma and it's hard for me to be outside). She starts dance lessons again this fall, and I'm going to look into mother/daughter yoga classes or something that we can do together.
I work at home; while I'm "at home," that doesn't mean I'm available 24/7 to just be with her. I have work to do that must be done, or I don't get paid. This is a source of contention in the household, as I'd like to see my husband take more of an interest in doing things with her (either that or do the household work, but I can't seem to get him to do that one either. Any suggestions? LOL).
I've had her enrolled in a Pediatric Wellness Fitness clinic, but I'm ambivalent on it. On one hand, it helps make her aware that she needs to exercise more and holds her accountable to do that exercise, and it makes her sit with a nutritionist and talk about what's good to eat, etc., etc., but when all's said and done, I can't force what she ultimately decides to put in her mouth or do for exercise. I supply the good, organic food; with her sensory issues, getting her to eat anything other than a very small group of "favorites" is NOT the easiest thing in the world. And our whole house eats organic, not just me and her (my husband and I have food allergies and intolerances). Getting her motivated to do anything physical is very, very challenging.
My daughter's build is such that she will never be small. She'll never be super thin. She has my husband's build and I suspect his metabolism; weight for her will always be something she'll have to watch. Her weight is in her tummy area; that has nothing to do with her chest, which is already 33 inches--and there's no fat padding there. She just has a big frame/big bones. Yes, she wears Misses clothes.
I try to stay positive and focus on good things rather than on how fat she is and how she has to lose weight. She's already aware of that; I don't have to remind her. She's not proud of her tummy, or the shape of her body and how hard it is to find clothes that fit but, unfortunately for her, her dad and uncle were "the exact same way" when they were her age. It's like some sort of family genetic curse or something. She also suffered horribly from earaches and all sorts of childhood illnesses and took a ton of antibiotics; I feel they, more than even her genetics, really screwed up her body and her metabolism.
So I feel your pain, because my daughter is the same way. Put her next to any of her cousins and there are no small bones on her frame. She seems to have gotten all the genes that are programmed for "BIG." BUT, big DOES NOT have to mean fat. I really, really believe that she will have a huge growth spurt soon where she'll shoot up four or five inches and then most of "the tummy" issue will be moot, because, like Gumby, she will have stretched. And if I keep watch over what she eats and her exercising, I believe we can come out on the good side in this race called "growing up." I have faith, and I try to instill my daughter with the same faith.
Good luck to you and your daughter.