You might not need to broach the subject at all. She is already declining desserts and seconds so you don't need to tell her to stop eating but you will need to protect her from misinformation. Most girls her age learn what they know about food from advertisers. They incorrectly believe foods carrying nutrition claims such as "low fat", "sugar-free" or "lite" are always better choices than regular foods, and your daughter may eat these highly-advertised foods thinking they do not count. I find snack foods and drinks marketed to kids her age can be a tremendous source of unnecessary calories.

Yes. Your pediatrician won’t bring it up unless it’s really an issue. So listen carefully. He or she looks at the height and weight chart to get your child’s BMI (body mass index), a measure of fatness. Your pediatrician is looking for a change. For example, if your child is in the 80th percentile for BMI, and suddenly there’s a blip and he’s in the 90th or 95th, something has happened. What’s going on? This is especially important if there are any health issues in the family, such as a history of heart disease.