Bethesda implemented children in Fallout 3 without any problems.
So there won't be a problem putting them in The Elder Scrolls V: Skyrim.
Indeed, any problems can simply be avoided by making it so that children are immortal, as was the case in Fallout 3, and I'll discuss that subject no further, due to forum rules. And I'm pretty sure Oblivion never had children to begin with, not that Bethesda put them in then removed them.
But anyway, I'd imagine that children will be handled similarly to in Fallout 3, in that they'll be NPCs that populate the world, sometimes they're just there to make the world feel more inhabited, other times, they might be involved in quests. Whether as quest givers, or quests where some NPC tells you to go save his child or something along those lines.