Ross, a writer,[1] referred to her as "Little Nell" (after a character in Charles Dickens' The Old Curiosity Shop) in his family life column in the Sydney Daily Telegraph.

[2][3] She also worked as a busker and as a soda jerk in a café, where her tap dancing is often noted as the reason why she was cast as Columbia in the original production of The Rocky Horror Show following an impromptu audition.

[4] She reprised the role in The Rocky Horror Picture Show,[5] released in 1975, and starred as Nurse Ansalong in the 1981 sequel, Shock Treatment.

The B-side of both of these releases became better-known, perhaps helped by a performance on British television in which she accidentally (and repeatedly) exposed her breasts.

A final single, "Beauty Queen" from the film The Alternative Miss World, was released on PRE Records in 1980.Campbell has also appeared in several stage productions, including the Off-Broadway play You Should Be So Lucky and the Broadway musical Nine.

In 1986, Campbell opened the nightclub Nell's on West 14th Street in Manhattan (New York) with Keith McNally and Lynn Wagenknecht.