Has anyone ever had an adventurer have kids during a campaign?
Yup. Our groups master hunter had a child, she hunted until the last month of pregnancy, but need help carrying kills back. Then we had to find a way to keep baby quiet once we got back to hunting again. Luckily, this kid was a born hero and learned quick. One other PC fathered children on twin sisters, and had to care for all of them.
Generally, in Lunar persecuted Sartar (& later in Tarsh once we fled Sartar, and Delecti's swamp once we fled Tarsh) the survival of the familes depended entirely on a larger group, and we really had to stick together and work hard to survive. It makes gaming that much more rewarding, to have a family together and watch it grow.