Herbert Wilcox used her as Frankie Vaughan's leading lady in The Heart of a Man (1959), then for Rank she starred in a romantic comedy Upstairs and Downstairs (1959).

"[9] She starred in some British comedies, Petticoat Pirates (1961) and Stork Talk (1962) then did three films produced by Stross: The Brain (1962), The Very Edge (1963), and 90 Degrees in the Shade (1965).

[10] Heywood starred in The Fox (1967), a screen adaptation of a D. H. Lawrence novella, which was produced by Stross and co-starred Sandy Dennis and Keir Dullea.

In Hollywood, she was the female lead in Trader Horn (1973), a failed remake of a 1931 classic film, then she returned to Italy for Love Under the Elms (1974).

[18] Heywood starred in Good Luck, Miss Wyckoff (1979), produced by Stross[19] and in the Italian satanic horror Ring of Darkness (1979).

Her penultimate role was as Manon Brevard Marcel in a two-part episode of the popular US television series The Equalizer, starring fellow British actor Edward Woodward, in 1988.

After their marriage in Zurich, Switzerland on 12 February 1960, the couple subsequently collaborated on several British and international films, including The Brain, The Very Edge, Ninety Degrees in the Shade, The Fox, Midas Run, I Want What I Want, and Good Luck, Miss Wyckoff.

In 1990, she married her second husband, George Danzig Druke, a former Assistant Attorney General of New York State, who died on 7 October 2021 in Beverly Hills, aged 98.