I’d seen a "rumor" a few weeks ago that she didn’t want to do the show anymore. There are too many loose ends like who are the Shadows and what do they want with Adien. Who are the Shineys.
I thought a couple of years ago when they introduced the Book of Changes and the Watchers it was beginning to look more like Charmed every episode. Then before Aiden was born she was told he was going to be more powerful just like Wyatt in Charmed.
On the other hand, Medium is turning into Ghost Whisperer where Allison and her daughter are being visited by ghosts in most episodes.