His third wife was Mary Raffray (née Mary Huntemuller Kirk, 1896–1941), a daughter of Henry Child Kirk, proprietor of the Kirk Silversmith Co. of Baltimore, Maryland and his wife, the former Edith Huntemuller, who dedicated her book Her Garden Was Her Delight to her memory.
Mary Simpson's letters, along with her sister's, are held at Harvard University Archives.

A girlhood friend of Wallis Simpson's, Mary Kirk was a bridesmaid at her first wedding and introduced her to Ernest Simpson in 1925; she also was the "other woman" with whom Simpson took a hotel suite in Bray, Berkshire, in order to give his wife evidence of adultery, so that she could bring divorce proceedings against him.
Ernest Simpson and Mary Raffray were married in the Diamond Jubilee ballroom of the Brooklawn Country Club in Fairfield, Connecticut on 19 November 1937, six months after the groom's divorce from Wallis Simpson and three weeks after the bride's divorce from Jacques Raffray, a French aviator (son of French explorer Achille Raffray), whom Mary had married on 29 July 1918.

Mary and Ernest Simpson had one child, Ernest Henry Child Simpson, who was born prematurely on 27 September 1939, and christened at the Guards Chapel, Wellington Barracks, London.
In June 1940, the Simpsons sent their infant son to the United States to escape the War including the Blitz.
However, a month before Mary's death he returned with her to England.
Mary Simpson died of breast cancer on 2 October 1941, at the couple's home in Wiltshire.
Their son changed his name legally to Aharon Solomons before being commissioned as an officer in the Israeli Army.
His third wife was Mary Raffray (née Mary Huntemuller Kirk, 1896–1941), a daughter of Henry Child Kirk, proprietor of the Kirk Silversmith Co. of Baltimore, Maryland and his wife, the former Edith Huntemuller, who dedicated her book Her Garden Was Her Delight to her memory. Mary Simpson's letters, along with her sister's, are held at Harvard University Archives.
A girlhood friend of Wallis Simpson's, Mary Kirk was a bridesmaid at her first wedding and introduced her to Ernest Simpson in 1925; she also was the "other woman" with whom Simpson took a hotel suite in Bray, Berkshire, in order to give his wife evidence of adultery, so that she could bring divorce proceedings against him. Ernest Simpson and Mary Raffray were married in the Diamond Jubilee ballroom of the Brooklawn Country Club in Fairfield, Connecticut on 19 November 1937, six months after the groom's divorce from Wallis Simpson and three weeks after the bride's divorce from Jacques Raffray, a French aviator (son of French explorer Achille Raffray), whom Mary had married on 29 July 1918.
Mary and Ernest Simpson had one child, Ernest Henry Child Simpson, who was born prematurely on 27 September 1939, and christened at the Guards Chapel, Wellington Barracks, London. In June 1940, the Simpsons sent their infant son to the United States to escape the War including the Blitz. However, a month before Mary's death he returned with her to England. Mary Simpson died of breast cancer on 2 October 1941, at the couple's home in Wiltshire. Their son changed his name legally to Aharon Solomons before being commissioned as an officer in the Israeli Army.
Ernest Simpson