Gladys Boon was trained as a nurse at Orange Hospital, having graduated with her nursing certificate in 1915. However, she soon resigned from her position here to work as a nurse at a military hospital in Sydney in December 1916, and eventually enrolled with the Australian Army Nursing Service (AANS) in mid-1917.
Requested by the British military, Gladys was one of the nurses sent to Salonika, Greece, to support the hospitals that had been established here to treat soldiers. Unlike most nurses serving from Australia, those at Salonika were not treating Australian soldiers, and would not do so for the length of their time there.