I would also say that if it has always been there it is pretty normal but if you are worried you could get it checked out.

Protruding bellies are actually a sign of an underweight child, which is fine if your child has been the same all the time, and on the same weight curve. But if she is getting skinnier etc... you may want to see a dietician about getting some ideas on how to get some weight onto her. That is when the belly will go in.

We use sustagen with Parker and that tends to work, in helping him gain weight.