She was born Marie Isobel French, eldest daughter of the Hon.
William Joseph French, a son of the 4th Baron de Freyne, and Victoria Louise (née Bellasis).
She was educated at Les Oiseaux, Westgate on Sea, Kent, and at Ware, Hertfordshire, by the sisters of the FCJ.
He was a son of Sir Anthony Weldon, 6th Baronet and the former Winifred Varty-Rogers.
[1] The Countess Cathcart died on 25 February 2015, aged 91.