I decided to try for the 15 children and 30 grandchildren badges before installing IP to try to find the messages in the bottle. I did get Exercise in Fertility (Gold). While going for Head of the Family (Silver), I thought I would take advantage of the 13 children who did not live at home. I used Edit Town to change households. I played the various children having them adopt or conceive 23 grandchildren. I had the 2 children who still lived with mom and dad adopt 7 children. I made sure that the last grandchildren were from those 2 children. Unfortunately, I did not trigger the badge even after having the 31st grandchild. I was not sure if I would break the chain by using Edit Town, but I think that is what happened.
Luckily, I did create a backup of the 15 children and will go back and have the last 2 children have all 30 grandchildren. My sims get very overweight if I don't stop them from eating all that birthday cake. (ETA - I think I will start a fresh game as I have since read the grandparent can't have a partner. Not sure if that matters but I am not going to go through another 30 children to find out.)
As an offside: Why would 15 children merit a gold badge but having 30 grandchildren, which takes longer, only merit a silver badge?
