The petite, dark-haired, pudgy Carr began acting in theatre when she was just past the schoolgirl age she was portraying, making her debut at the age of 15 in the Sheffield Playhouse production of "The Spider's Web". It was not until 1986 that she ventured to the US when she played several key roles (Fanny Squeers, Miss Snevelilli, and Peg Sliderskew) in the heralded revival production of "The Life and Adventures of Nicholas Nickleby" which played Broadway and toured the US. Carr remained in Los Angeles when the troupe returned to England and began acting in TV projects, returning to the L.A. stage in a 1995 production of "She Stoops to Conquer", for which she won a Los Angeles Critics Award.

Prior to her TV work in America, Carr had made appearances on British productions, including the famed series "Upstairs, Downstairs", and acted with Lord Laurence Olivier and Joan Plowright in the BBC production of "What Mad Pursuit". Her first American TV-movie was the less high-brow "Return of the Shaggy Dog" (ABC, 1987) for Disney and after her sitcom success, she found a niche doing voices for animated series, including "The Fantastic Four".