Mary Cholmondeley, Lady Delamere

Ruth Mary Clarisse Cholmondeley, Baroness Delamere (née Ashley, formerly Cunningham-Reid and Gardner; 22 July 1906 – 10 October 1986), was a British heiress and socialite. A granddaughter of German-Jewish banker Sir Ernest Cassel, she inherited an estate including a large manor house in Six Mile Bottom and half of her grandfather's fortune (valued at approximately £50 million in 2020). The Cincinnati Enquirer referred to her as "England's wealthiest girl" when reporting on her first marriage to Captain Alec Cunningham-Reid. She was married three times, becoming a peeress upon her third marriage to Thomas Cholmondeley, 4th Baron Delamere. Lady Delamere was the younger sister of Edwina Mountbatten, Countess Mountbatten of Burma.

Early life and family Lady Delamere was born Ruth Mary Clarisse Ashley on 22 July 1906 in Stanmore. She was the youngest daughter of Colonel Wilfrid Ashley, 1st Baron Mount Temple and Amalia Mary Maud Cassel. Her older sister was Edwina Mountbatten, Countess Mountbatten of Burma.

She was described by her niece, Lady Pamela Hicks, as "rather excitable" and "flighty". They had two sons, Michael Duncan Alec Cunningham-Reid and Noel Robert Cunningham-Reid.

On 3 September 1940, she married a second time to Major Ernest Laurie Gardner. They divorced in 1943.