Perhaps her most famous catchphrase was "many, many, many times", delivered in the dry, reedy tones of Bea Clissold, the ancient actress who was renowned for having given pleasure to many, particularly in "The Little Hut" on Shaftesbury Avenue.

Marsden's vocal range was impressive and also included the husky Daphne Whitethigh, the strident stereotypical Aussie tones of the ultra feminist (but conflicted) Judy Coolibar, and the cut-glass Received Pronunciation of Dame Celia Molestrangler (in a series of loose pastiches of the stilted dialogue in 1930s and 1940s romances and melodramas – for example, The Astonished Heart became The Hasty Nose – partnered with Hugh Paddick's 'ageing juvenile Binkie Huckaback', with the denouement inevitably bringing the lovers crashing back to earth).

In 1958, Marsden played the Fairy Godmother, in Rodgers and Hammerstein's Cinderella at the London Coliseum with Tommy Steele, Kenneth Williams, Yana and Jimmy Edwards.

She later played Hermione in Britannia Hospital (1982),[4] Violet Manning in The Dresser (1983),[5] Princess Troubetskaya in Anastasia: The Mystery of Anna (1986 TV movie), and Mrs. Barnacle in Little Dorrit (1987).

She was believed to be recovering, but died suddenly while socialising with friends in the bar of Denville Hall, a retirement home for actors, in Northwood in London.