When I first began moodling the main characters in my murder mystery series  - a high-powered attorney who is a partner in the family law firm, and his new bride, a child psychologist and writer - they were mostly just the perfect couple on whom I could hang my social justice plots. But the two of them had different ideas about how their relationship, and their life together, would develop. First, both developed a strong focus toward building their rural kingdom (it's just a setting, damnit!), and before long, having children and raising a family became a huge issue, especially for my heroine. How do characters take over like that? Soon I found myself searching for photos of the perfect redheaded boy to enter the story (perhaps in book #3 after the heroine suffers some fertility anguish?), instead of teaching readers about the dangers of GMO crops, fracking, and other really important stuff. Children add elements to fiction that completely change the dynamics of a story...