Gherhartd Sildoenfein my experience is that 95%+ of the time players love it when you give them things to bite, and things that bite back. As long as the kids are done in ways that matter, but that don’t necessarily suck time or focus out of balance with other aspects, folks generally are very positive about it — even if they wouldn’t have thought about it before hand.

Really, it’s like dealing with historical information in games like Pendragon or SotI. If you do it well, make it part of the world, make it matter, let players interact with it in ways that give them choices, most folks will like it, or at least roll with it. It’s only when you want them to get into the details of what type of tang their cloak pin has on it and how that wasn’t actually invented until the 950s, and this is the 910s, that folks get irked. Similar with kids.

And the other 5% of the time… I gotta go with Paul. Harsh but true. If someone objects to kids being part of the world, I’mma point out to them that there are other people they can play with.