The program's creator was Mary Grannan, a Fredericton, New Brunswick primary schoolteacher, who often composed stories and plays for her classes. After a couple of years of doing Just Mary locally, the popular children's show moved to the network in October of 1939, and by 1940, Mary had moved to Toronto, where she wrote several other programs, including Maggie Muggins and Children's Scrapbook. Lou Snyder was the organist on her programs for 23 years. Mary was famous for her big hats and enormous earrings. She retired in April of 1960, and died 15 years later at age 75.