Thanks, Granade, changing it! (For record only, the original post was myself quoting FunsizeNinja123 post above. Sorry about that, not doing it again.)
So, about the less controversial and noped parts of the idea… in other words, children.
My problem with it is mainly, the gestation and birth cycle is different depending of the character’s sex. If you character is a male(and Cataclysm’s future being one where technology don’t allow a man to be pregnant, etc, etc…)(quick change here, your character can be a woman in this case as well, just not pregnant. 2am, leaving…), you will have through… three seasons? a Female NPC Companion to take care of during a post-apocalyptic future. She will need to have more food, care and protection, since as the gestation goes, more and more resources of her body are there to take care of the baby, not herself.
But being a female, you are the character who will need protection of another NPC(same-sex or other-sex couple) through three seasons. You are the character who will have strange needs, burst of behavior change and needs. And as we can see, going around surviving in the Cataclysm is a serious healthy risk, so…
…conclusion: remembering that we won’t see any kind of infrastructure regarding sex in the game, pregnancy could be, in a future when NPCs are more fleshed out, included as a Challenge scenario? Starting the game as part of the couple and having to deal with it, the Mission system could be used to the needs of yourself/your partner. And also, man’s pregnancy to make this equal, independently of how’s your character(as possible). Also, some small time skip passing through the more boring final parts of the gestation.
And, of course, the babies. It doesn’t even have to be a baby, i… don’t know about the community’s opinion about children in game, but let’s suppose that nope, no living children either. In this case, the question is not about “ok, taking care of children”, but “taking care of a developing NPC”.
One game that’s the blazing example of doing good work with IA is the Creatures series, where the player take care and teach… creatures :p… how to survive and take care of each other. BUT the IA itself was an amazing case of using Artificial Neuron Nets(it was the nineties!), and i don’t know about how much work it would take to use as a base in Cataclysm:DDA, except that it would be at least, a lot.
But for the sake of discussing, having a developing NPC(animal companion, robotic growing module, human child, you choose) would be a BIG Challenge, for years and years in-game as it grows and becomes a fully fleshed NPC, with quirks, experiences and abilities. At start, it would need lots of care and careful planning, since it’s wouldn’t be able to fend by itself well and it would be learning about how to do stuff, but as time passes, it could make you proud 
Or die because of a turret, or a Nether spawn, or fire or… well, you got the idea.
It’s nearly 2am for me, so i will develop it better later. Opinions? If this thread will be closed, i will create a new topic for this.