 London-born Smith became involved in television production when she directed the series "Suspense" in 1962.She went on to direct popular BBC shows such as "Z Cars" (in 1962) and "Doctor Who" (in 1966), for which she directed the stories "The Smugglers" and "The Underwater Menace".In 1967 she directed an adaptation of "The Railway Children" with Jenny Agutter that was successful enough for it to lead to the fondly remembered 1970 film in which Agutter reprised her role of Roberta.