Harvest Moon: Animal Parade "Wizard Wants A Baby!"

After marrying the Wizard and having him up to 15 hearts, he will ask you about having children. If you say no, the Wizard will lose affection - but he will keep asking you until you say yes. If you say yes, he will ask you what gender you'd prefer. If you don't have a preference and you can just ask Wizard. Whatever he ends up saying is the gender of child you will end up getting. If you choose the gender of the child, that's the gender you will get. Keep up the Wizard's affection, and keep checking your calender. After 2 weeks or so the birth date should be set.