K.N.
It's very difficult to encourage a young child to lose weight. Chances are it's only going to hurt their self esteem and make matters worse. Not that by any means you would do that on purpose so please don't take it that way. My step daughter was severely overweight when I came into the picture (70 lbs, age 4, average height) My 8 year old son weighs less than that. What I did was put the whole house on a healthy living routine. NOT a diet. I tossed all junk food (ok i kept a well hidden mommy stash but still)stopped buying prepackaged foods and switched to whole foods and lots of raw fruits and veggies for snacks and at least once a week we went on an active family outing where we walked or hiked or something. I also set a specific time where they could watch tv, or play video games ect and kept it short so they would be more active. It was good for all of us Dh even lost needed weight, though for some reason it took a lot more than just those changes for me to. But if you offer healthy options, keep her out of the kitchen unless she's helping prepare meals and giving her healthy snacks and proper portions you should be able to do it just fine. Just remember though that encouraging a healthy lifestyle for your whole family is going to get you better results than trying to get your daughter to loss weight.