What if she writes a tell all book exposing his scam. 
Doubtful....
There is a lot of money involved. And children and grandchildren.
Chances are....her divorce settlement(if she's getting more than half of all those deeeelicious millions) will be contingent on not mentioning a whole bunch of stuff in a "tell-all book".
She's entitled to at least half - if they get divorced in TN - of everything he's made and acquired the last 40 years. Maybe even more, due to length of marriage, and her age. I'm sure there wasn't a pre-nup....they've been together since high school.