too heavy for her age?

I wanted to get some advise on how to help me maintain my daughters diet.. she just turned 4 yrs and my doctors states she is 20lbs overweight, for now I tend to have her dinner very light and early on so that she doesnt sleep on a full stomach.
what else is good to do? thank you.
also I do feel that in the future if I keep her active she will eventually grow out of her weight

[Renee Radenberg]

Her weight is very much above the 95th percentile and her height is on the 95th percentile for her age. It is recommend increasing children's physical activities (play, dance, sports) to lose weight, and not lower calorie intake due to the need of calories for growth. For her age she needs approximately 1800 calories a day to grow. Limit time in front of the TV or non-active-video games. There have been studies showing the longer the length of time a child sit in front of the TV, the greater the weight gain. Limit high sugar drinks/snacks, and try replacing with low fat milk/yogurt, fruit, air popped popcorn, or low-fat cheese. Additional suggestions: cook only low fat meats (chicken, fish, loin of pork) or non-meat sources (soy products, nuts), low fat vegetarian combinations (rice & beans, pasta & beans, low fat cheese & pasta), fat free or low fat dairy products (skim milk, 1% milk, low fat cheese, low fat yogurts, low fat soy milk/yogurt), use plant oils, non trans-fat margarines, and eat a lot of fruits, salads, and vegetables. Eat daily high fiber breads and cereals (oatmeal) and limit ‘junk’ foods.