there can be only few causes for a fat stomach in a child. It can be fluid or fat or any organ enlargement. If your child is otherwise well without any other symptoms suggestive of any illness, it most probably due to fat & she is overweight
. It can be genetic in most condition. She will need evaluation for her cholestrol
levels. treatment wise good & healthy diet including plenty of water, low fat like minimise oil/ghee etc, more fruits & vegetables, cut down on junk foods like chips, bakery foods llike cakes, pastries etc. have a consult with a dietecian and stick on to a good health diet.