Error's one of having 20 grandchildren, that is. She already had a lot of children (10 in the story so far). Later she had 3 more (me mentioning those isn't exactly a spoiler, because, even though they might pop up in the story eventually, they will never have actual roles in the plot). I made her have more after the 10 kid mark just because I'm really fond of her, and she kept rolling wants to have a baby. Yes, her husband is a Romance sim, but he didn't really mind much. He only starts paying attention to his children when they reach childhood or so, but until then, Error does a good job of raising them.
( More babbling and mention of Error's numerous descendants under the cut )