One of three children born to the respected Scottish actor Andrew Cruickshank and his second wife, Marty attended the Francis Holland School in London before following in her father's footsteps by attending the Central School of Speech and Drama for a year and graduating from the newly-formed Drama Centre in 1963. She made her television debut three years later and has played a wide variety of roles in populist dramas such as 'The Bill', 'Midsomer Murders' and 'Kavanagh, Q.C.', like her father essentially a versatile character player rather than a star actor. On stage she has been acclaimed for playing parts as diverse as Gertrude in the Royal Shakespeare Company's 'Hamlet' and the real 'Charley's Aunt' in a touring version of the durable farce. She has also written plays, including 'The Princess of Cleves', directed by Tim Albery at the Institute of Contemporary Arts and 'The Royal Borough', directed by Simon Curtis at the Royal Court Theatre, London. She also penned a short film for Channel 4 television called 'Bathing Elizabeth'.