I'm on my 3rd game. First two my wife was popping out kids left and right. This time, 3rd year of marriage and no children. I've tried having her in my party, leading her own party and following me, in my town with me waiting in town for days, everything.
I'm going to assume it's bugged until we discover some type of hidden infertility stat (which would be BS, imo). So I'm just going to use the developer console to make my wife pregnant to get a few children.
If anyone else has this issue of a wife not getting pregnant for years, just grab the dev console mod and in game press ctrl+shift+~ to bring up the console, then type campaign.conceive_child