She taught English literature in teacher training and (from 1962 to 1970) as a college principal for 24 years before turning to full-time research and writing. She is a well-known writer in Esperanto. Boulton in her later years was president of two Esperanto organisations, Kat-amikaro[4] and ODES.[5]
She was the author of Zamenhof: Creator of Esperanto — a biography of L. L. Zamenhof published in 1960 by Routledge & Kegan Paul of London. She also wrote a widely-used series of introductory texts on literary studies: The Anatomy of Poetry (1953), The Anatomy of Prose (1954), The Anatomy of Drama (1960), The Anatomy of Language (1968), The Anatomy of the Novel (1975) and The Anatomy of Literary Studies (1980). Her first book was Preliminaries: Poems (1949). Later books of poetry, as well as short story collections, were in Esperanto, which she learnt in 1949.[1] She wrote as well Saying What We Mean (1959), Words in Real Life (1965) and Reading in Real Life (1971). She had also translated Harivansh Rai Bachchan's Madhushala (1935) to English.
From 1957 to 1962, she became the secretary of the International Summer University (ISU), which took place annually as part of the Esperanto World Congresses. From 1961 to 1967, she was secretary of the Esperanto World Federation (UEA) Commission for International Examination. For 25 years, she ran the summer Esperanto courses in Barlaston, south of Stoke-on-Trent. She was chairwoman of the Society of British Esperanto Teachers (1969) and a member of the Akademio de Esperanto since 1967.[6]