Sharon also has a history of her own health problems which may be causing her issues as well. Ozzy's aging and it's been really apparent that he has some long term effects from his alcohol and drug abuse. I'm sure as he ages she needs to address that as well her children's issues that happen occasionally.
I always got the impression that Sharon continued to work because she's been really driven for a chunk of her adult life. She never struck me as someone who is content to just be at home especially now that her kids are grown and out doing their careers. It opens up the door for her to do that. I can empathize with her. If I had all the money in the world I'd still be working too because I need to feel like I have some purpose.