Rogue One Sequel

Like what? Repairing? When she worked as a mechanic at a space junkyard? Fighting? When she lived in one of the most cutthroat places in the galaxy and had to fight to survive? You're gonna have to be more specific.

Flying a spaceship, using her force powers after just discovering them, using a lightsaber which is very difficult for those who are untrained to use.

In the novelization of the movie (god, that sounds pretentious), it's explained that she learned how on simulations and the sheer need to. Working at the junkyard meant she'd need to develop skills like piloting to help move ships, and I dare say there wasn't much else to do on that back water planet than hone skills. And about her force powers: Luke did the same thing with no training, except no one was trying to murder him, so I think the sheer pressure on Rey also had a part to play in that.

Was the novelization released after the movie or before the movie?

After the movie, I'm sure.

It was probably made like that as a form of damage control.

Perhaps, but that doesn't change the fact it's still existing Star Wars continuity.