What a fun book. I remember seeing the movie several years ago, with Merle Streep as the ethereal romance writer, Roseanne Barr as the spurned wife, and Ed Begley Jr. as the adulterous husband.
When the husband, an accountant, leaves his lumpish wife for the beautiful romance writer, the wife decides to get revenge. Little by little she destroys his job, steals all his money, burns her house down. and proceeds to the next level. She turns her eyes to the writer, dumps her children on her, starts a course of body-enhancing plastic surgery, and enjoys life.
The book is as much fun as the movie, as the She-Devil of the title moves step by step to destroy the happiness of her husband and his lover.