She served in France in World War I and received the Medaille de la Reconnaissance Française (Medal of French Gratitude).

She was the eldest of the eight children of Samuel Gray, a clothing manufacturer from Cavan, Ireland, and his English-born wife Amelia, née Bird.

[1] In February 1915, Gray enlisted in the Australian Army Nursing Service, and ten days later left for England.

[2] When she arrived in England she found that the mansion which had been offered for use as a hospital, Harefield Park House in Middlesex, had not been prepared and was not ready to be used.

[4] Gray's wartime diaries span the years 1915 to 1919 and include descriptions of visits to her hospitals by dignitaries and royalty, as well as stories of deaths of patients.