Honestly, good for her. She rode the wave of that pop music at the right time, made a huge name for herself, transitioned it to movies and now tv and is getting ready to step away from that as well.
She did it all in a period of 15 years, seemed like she had a lot of fun doing it, found the wrong husband then the right one and now has a kid. All before the age of 40.
She's stepping away to hopefully go live a more normal life knowing if she wants she can dip back into that well again and show up at Coachella or some other big name festival to get a pay check.
It's better to step away and leave people wanting more than try to force yourself to stay relevant and find yourself playing to empty stadiums.