No. I really did not like kids in Fallout. Though it doesn't make much sense, having nothing but advlts and no kids, making it impossible to reproduce, I prefer they keep it like in the other games.
The absense of kids in computer games has been rather well documented ( :hubbahubba: ), and yet games haven't exactly had a problem with popularity as a product (i.e. very few people have complained about the lack of children in the past). As such, I wouldn't say that "making sense" is necessarily a requirement for a game becoming popular (although it never hurts, as long as you're adding it in correct amounts).
Ditch the kids, they add little to the game other than slightly more realism that isn't the focus of most players anyways. Or at least don't oversell it, it's not that big of a deal, Bethesda.