She was born in 1916, as Sophie Mary Trafford, daughter of Maj Sigismund William Joseph Trafford (d 1953), of Wroxham Hall, Norwich, by his wife the former Lady Elizabeth Mary Constance Bertie, OBE, daughter, by his 2nd wife, of the 7th Earl of Abingdon (1836-1928).
Her husband was 29 years old, and a temporary captain in the 1st Battalion, Scots Guards, British Army during the Second World War when the following deed took place for which he was awarded the VC.
During the period 22–27 April 1943 near Dj Bou Arada, Tunisia, Captain Lord Lyell's outstanding leadership and gallantry enabled his company to take its objective. On 27 April accompanied by a sergeant, a lance-corporal and two guardsmen, he led an attack on an enemy post consisting of an 88mm gun and a heavy machine-gun in two separate pits. He destroyed the crew of the machine-gun with a hand grenade and then, three of the party having become casualties, and with the lance-corporal to give covering fire he leapt into the second pit, killing several of the crew before being overwhelmed and killed. Both the guns had been silenced.
Lady Lyell's son, Charles, the 3rd Baron, was born 27 Mar 1939.
Lady Lyell's funeral takes place on 19 June at Kirriemuir Old Parish Church.