u/Thick-Association305

I've been playing the game (demo) for like 5 hours and my line always dies out at the third or fourth generation. I don't know how to prevent this, I try to get them married as soon as possible but they're always attending someone's wedding or funeral or coronation, by the time they can have babies, theyre too old to and my line dies out, sometimes they're not even busy and just won't have children. I also rarely have a couple beyond the first generation (the default couple) have more than one child, any tips?