"The Inseparables" by Stuart Nadler

By Amazon.com: 

"In less than a year, Henrietta lost her husband and most of her money, her divorcing daughter has moved home to the house she needs to sell, and she's about to lose her hard-won anonymity: The Inseparables, her scandalous and critically despised decades-old bestseller, is about to be reissued. And things only get worse."