Before she was 2 years old the family moved to Ealing, West London, where they lived for nearly forty years. She and her sisters went to private schools and attended Ealing Congregational Church. The six Dunkerley children in order of age were: Elsie, Marjory (Maida), Roderic, Theodora (Theo), Erica and Hugo. The family lived in five different houses during their time in Ealing and moved to Worthing, Sussex, in 1922. She took the surname Oxenham as her pen name when "Goblin Island" was published in 1907. Her father, William Arthur Dunkerley, had used the pen-name "John Oxenham" for many years prior to this.