LOL.Kids are scarcely end-game feature, you can easily get a wife while not being a vassal, and she often gets pregnant almost 3 days after you get married. By the end-game I have 11 kids from 2 different wives (one of them died in childbirth) and 9 of them are already 27-30 years old. Children need fix, as long as all lords should be able to marry and make kids too. Right now my mid-game looks ridiculous - 94-years old Derthert still riding and fighting against 76-years old granny Rhagaea.
By the way, I do not insist, but I'd be very grateful if you would provide me the link for that dev blog.