Kathleen Erin Hogg was born on June 3, 1939, in Alexandria, Louisiana, she was the youngest of eight siblings by Gladys (Coker) and Charles Wingrove Hogg, a disabled World War I veteran. She long relished creating original narratives, and by age 6 was telling herself stories at night to help herself fall asleep. At age 16, she met U.S. Air Force Second Lieutenant Ross Eugene Woodiwiss at a dance, and they married the following year. She wrote her first book in longhand while living at a military outpost in Japan.
She is credited with the invention of the modern historical romance novel: In 1972 she released The Flame and the Flower, an instant New York Times bestseller that created a literary precedent. The novel revolutionized mainstream publishing, featuring an epic historical romance with a strong heroine and impassioned sex scenes. The Flame and the Flower was rejected by agents and hardcover publishers, who deemed it as "too long" at 600 pages. Rather than follow the advice of the rejection letters and rewrite the novel, she instead submitted it to paperback publishers. The first publisher on her list, Avon, quickly purchased the novel and arranged an initial 500,000 print run. The novel sold over 2.3 million copies in its first four years of publication.
The success of The Flame and the Flower prompted a new style of writing romance, concentrating primarily on historical fiction tracking the monogamous relationship between a helpless heroines and the hero who rescued her, even if he had been the one to place her in danger. The romance novels which followed in her example featured longer plots, more controversial situations and characters, and more intimate and steamy sex scenes.
She was an avid horse rider who at one time lived in a large home on 55 acres (220,000 m2) in Minnesota. After her husband's death in 1996, she moved back to Louisiana. She died in a hospital on July 6, 2007 in Princeton, Minnesota, aged 68, from cancer. She was survived by two sons, Sean and Heath, their wives, and numerous grandchildren. Her third son, Dorren, predeceased her.