A free mod for Mount & Blade II: Bannerlord, by Windwhistle.
Bastard Children is a mod that lets you have children with any other character in the game, regardless if they are wanderers or notable characters. It’s also great way to get some extra income, even if you’re a bad guy. It’s a nice way to get some loyal followers, too.
To use this, first, you need to download the mod and install it. After installation, you’ll be able to create a child with any other hero in the game. You can have a boy or girl with any other character.