People always say that having one kid of each gender is the "perfect family".
But the fact is that if you have one boy and one girl, the boy won't ever have a brother and the girl won't ever have a sister. That's a wrinkle I hadn't thought of when we first decided to stop at two kids.
If you have one kid of each gender, would you be sad that your son wouldn't have a brother and your daughter wouldn't have a sister?