Lumley spent three years as a photographic model, notably for Brian Duffy, who photographed her with her son, born in 1967. Also that year she appeared on the BBC2 programme The Impresarios: For Appearance's Sake, explaining Duffy's studio process and her joy in working with him.[10] She also worked as a house model for Jean Muir. Over forty years later, she participated in another photoshoot – again with her son – for Duffy as part of a retrospective of the photographer's work.[11]
Lumley appeared in an early episode of the Bruce Forsyth Show in 1966. She appeared in a British television advertisement for Nimble Bread first screened in 1969.[12]
Lumley did not receive any formal training at drama school. Her acting career began in 1969 with a small, uncredited role in the film Some Girls Do, and as a Bond girl in On Her Majesty's Secret Service, in which she had two lines as a British girl among the villainous Ernst Stavro Blofeld's "Angels of Death".