Gardner was born in Chesham, Buckinghamshire.

[1] She made her stage debut immediately on leaving school and by age 18 had achieved success there.

She was seen by Alexander Korda (her future brother-in-law) who signed her to a five-year film contract at London Film Productions, with Wedding Rehearsal being her film debut as one of the Roxbury twins.

She died in Beverly Hills, California, in 1999 at the age of 84.

Gardner was married to Zoltán Korda and together they had two sons, David and Nicholas.