Agatha Le Breton, better known under her pseudonym Miriam Agatha, was educated in Maryborough and Townsville. From 1906 she taught in various Catholic schools in Sydney and in Queensland and used most of her spare time writing short stories and, later, a children's novel, Nellie Doran, which was published in 1914. In 1917 she transferred to the NSW Education Department and taught in state schools until she resigned in 1934 to concentrate on writing. Le Breton published numerous short stories, mainly for children, in Catholic publications. She was a regular contributor of stories to the Messenger of the Sacred Heart (as Miriam Agatha) to the Far East (as Mickie Daly) and to the Annals (under her own name). Some were published separately as Australian Catholic Truth Society pamphlets. She used another pseudonym, Henry Somerville, for the short biography Apostle of Organised Charity: St Vincent de Paul [1916?]. She was also the author of textbooks, including the reader Billy and His Dog (1921).