[1] Frankau's first television appearance was in an episode of the BBC's Sunday Night Theatre (1954); she acted in Emergency-Ward 10 and The New Adventures of Charlie Chan, both in 1957.

Other TV appearances include roles in The Man Who Finally Died (1959), No Hiding Place (1962), Six Shades of Black (1965), You Can't Win (1966), Intrigue (1966), Callan (1967), The Dustbinmen (1970), General Hospital (1973–75), Within These Walls (1975), Robin's Nest (1977), The Duchess of Duke Street (1977), Yes Minister (1981),[2] I Remember Nelson (1982), Nobody's Hero (1982), The Cleopatras (1983), Mitch (1984), No Place Like Home (1984–86), Terry and June (1979-1987),[3] Bergerac (1987), Boon (1990), 2point4 Children (1993),[4] and Big Women (1998).

The play was directed by Peter Hall and starred Judi Dench and Ian Richardson.

Her father was the actor Ronald Frankau, and her mother the actress Renee Roberts who played Miss Gatsby in Fawlty Towers.

They had two sons, Matthew (born 1969) and Sam Bain, a comedy writer who co-created Peep Show.