Educated at the University of California, Kathleen married Charles Norris, brother of the author Frank Norris, in 1909. She was a prolific author, producing over 80 novels in addition to numerous short stories and articles. Norris was a regular contributor to leading magazines such as Atlantic and Ladies' Home Journal. Her first novel, Lost Sunrise, appeared in 1909 and was immediately popular. By the end of her career her books had sold over ten million copies and made her the highest paid female author of her day.