Kids in RPGs

I don't mean kids playing RPGs, but do you actually have very many kid NPCs in your games?

Pros: Realism, important motivation source for many of the adult NPCs in the game

Cons: Problem of violence against children, maybe too gritty

How prominent should children NPCs be in a game where there is a lot of violence?

Fallout 3 had some child NPCs in it, but generally they were more comic relief than actually important in the game.