Izola Forrester, née Wallingford, spent her early childhood touring and performing with her mother, Rita Booth Henderson, a stage actress. Her father was George Wallingford Hills, a travel writer. Izola was raised partly by her stepfather, Alexander Henderson, a director of light operas, and then by George Forrester, a journalist, and his wife Harriet, who adopted her in 1893 after her mother's death. Her career as a writer and editor began at age 15 in Chicago. There she met Reuben Merrifield, an artist, whom she married in 1899. She got a job as a feature writer for The New York World, specializing in "women's interest" stories about public figures, and was also a regular contributor to many periodicals such as The Saturday Evening Post, Fireside, and McClure's. She also wrote more than 20 books, including the popular Greenacre Girls series and the Polly Page series. She became a pioneering female screenwriter in Hollywood with her second husband, playwright Mann Page, whom she married in 1913. They collaborated on 36 films ranging from the silent era to the talkies. She also was the mother of eight children. Her final book was This One Mad Act: The Unknown Story of John Wilkes Booth and His Family by His Granddaughter (1937), a memoir of her mother, who believed herself to be the daughter of John Wilkes Booth.