"Her" by Laura Zigman is a romantic comedy about a woman's obsession with her fiancé's ex-fiancée, Adrienne. Elise meets Donald on a flight, falls in love, and gets engaged, but her life is turned upside down when Donald's ex-fiancée, Adrienne, enters the picture. Adrienne is described as the "mother of all exes," and Elise becomes obsessed with her, convinced that Adrienne is trying to win Donald back. This leads to Elise stalking both of them and adding up clues that suggest an affair. The book explores themes of jealousy, self-doubt, and the complexities of relationships, with a writing style that combines humor and relatable observations on the challenges faced by women in relationships. The book is often described as a "chick lit" novel.