Cable is one Marvel Comics character that’s generally considered to be one of Scott Summers’ children. The latter is a superhero who shoots optical laser but can’t control it on his own so he relies on a special device in combat and his wife or girlfriend is Jean Grey.
They do have children but they almost always are byproducts of complicated plot devices. Cable was born to Jean Grey’s clone whilst Rachel and Nate Grey come from alternate worlds altogether. While Nate Grey did become a separate character, there’s enough evidence suggesting that he’s intended to be Cable’s doppelganger.
There have been times whenever cartoonists depicted a younger Cable, he looked like Nate. The closest analogy would be between Superman, Supergirl and Power Girl. Just as Supergirl’s derivative of Superman, Power Girl’s derivative of Supergirl and either one of them risks being redundant.
Writers would try to differentiate them but it’s a Catch-22 if only because of the initial intentions being built onto them. I guess that could explain why it’s so hard to bring Nate Grey back when you have Jean, Rachel and Cable fulfilling such roles on their own.