Did Palpatine have a wife on the side?
The Rise of Skywalker
Okay, you ignored the spoiler alert, so you already know that Rey is Palpatine's granddaughter. The Emperor had a son and a daughter. How? Well, what do you mean? The Sith Lord spent 15 years, and perhaps longer, plotting how to destroy the order of the Jedi and change the Republic into the Empire. Then, he introduced the reign of fear in the galaxy, designed the Death Star and all that. And had a family at the same time? Ok, how did he lose track of his children?
"I'm leaving you!"
"Don't be silly, I love you."
"You are an evil Sith Lord!"
"Who told you that? That little frog, Yoda? I provide for this family!"
"And I don't like your friend, the panting one, he creeps me out."
"Who, Vader? He works for me, be reasonable for Christ sake."
"I've had enough. I'm taking Jimmy, you do as you please."
And then? He stopped paying child support, drank a little, she moved to another city... why couldn't he find her? He could have been every voice in Kylo Ren's mind, control everyone from behind the curtain, know everything, anticipate everything, yet he sent a single henchmen to retrieve his family?
I'll tell you what happened. After The Last Jedi, Disney writers and Abrams probably met with Lucas (this is actually a fact). And he said (this is no longer a fact): "Dudes, this story is about Palpatine." And they said "Ok, the fans will love it." They nodded their heads and began to wonder how to include this in the plot.
Anton Pavlovich Chekhov wrote about the gun on the wall. If someone wants a rifle to go off in the third act, they should hang it on the wall in the first one. I bet dollars to doughnuts that when The Force Awakens was premiering, no one at Disney thought to call Ian McDiarmid. The reason for the Sith Lord's return being so flat was that it came from left field. None of the previous eight episodes gave but a hint of something like the history of Palpatine's family. It's really not difficult to surprise people – the art of it lies in having a good idea for it.
Chekhov himself explained that introducing elements that have no significance further in the story makes no sense.