Worldbuilding with Elderly and Young

A timely topic because in my personal, actual world, I now have a new grandbaby, and have been spending huge amounts of time where he lives.

So as I understand it (running on not too much sleep here, folks), this week we're to discuss whether we include older and younger folks in our books as secondary characters, or just the stalwart heroes and heroines? Well, there's a running joke between my editor and me that I tend to add a child to every book, whether the plot needs one or not, so....

My first scifi romance, Wreck of the Nebula Dream, is my futuristic version of the sinking of the Titanic, and as such, I definitely included children, Paolo and Gianna, a brother and sister who were my tribute to all the Third Class children who perished on Titanic. Every single adult main character in the book is dedicated to ensuring these two survive, and the children also have their key moment to be front and center in the plot. There's also a very elderly woman, Lady Damais, who is part of my small group of passengers trying to find a way to get off the Nebula Dream and survive.

My second published SFR was Escape From Zulaire, and one of the main plot points is that the human heroine, Andi, is trying to save the toddler son of the planetary ruler. She and the child and a small group of Sectors soldiers are trapped behind enemy lines when warfare breaks out.

My third SFR was Mission to Mahjundar and my editor put her foot down about why was there a child in the book and what plot point was he supposed to be advancing? I realized I'd written so much about him that at times the entire focus of the book drifted away from the hero and heroine. The thing was I'd given this boy such a great backstory....but it wasn't needed. I tried editing him out of a chapter entirely, as a test, and yup, you'd never miss him. So he was deleted entirely. Nothing is ever lost, of course, so maybe he'll show up in another book in the future, where he does belong.

Since then I watch out for my apparent inclination to add a child to the mix. I guess the point to me is that I include whatever characters are necessary for the plot to advance, and I happily assume all the rest of the population of the universe is happily doing their thing offstage.