The current plan is to introduce the children during the time skip, so that the player knows what they're like, and then eventually you get to choose who your successor will become.
A rough draft for the children already exists, and the CGs for the children of side characters are in the works and posted on subscribestar as previews for pledge rewards. (My hope is that this'll generate some more subscribers, and this way pay for the creation of this huge amount of artworks. We'll see how it works out.)
You can see a summary of the designs for the children sorted by the CG room pages here:
