She worked for two years as a critic and contributing editor for New York magazine. In 1970 she was the first recipient of the Catherine Pakenham Award for her journalism, and at the age of 24 edited Queen Magazine, also becoming Arts Editor of the Sunday Telegraph Magazine.

In an interview for the Sunday Times Magazine (published 11 November, 1990), she admitted having written nine pseudonymous Mills & Boon romances before publishing her block-buster novel Destiny in 1987.

Beauman's first work of non-fiction was Henry V (Pergamon Press, 1976), a study of the Royal Shakespeare Company's 1975 Centenary production. In 1982, to coincide with the opening of the Barbican Theatre in London, the Oxford University Press published her study of The Royal Shakespeare Company: A History of Ten Decades (ISBN 0192122096), chronicling the turbulent history of what was to become the RSC from its first founding as a worthy provincial company at the Shakespeare Memorial Theatre in Stratford upon Avon in 1879.