Robertson was in England in July 1914 when war broke out, and as she was a trained shorthand typist with St John Ambulance training, she volunteered with the Red Cross. She returned to Australia later that year and took a job with the Australian branch of the Red Cross. Her first verses and prose (mainly war themed) appeared about this time in The Age, The Argus, The Book Lover and The Bulletin, and some were later gathered together in An Anzac Budget and Other Verses (1916). She continued to write and be active in the Red Cross until she resigned in 1938, having been awarded an O.B.E. in 1918 for her work. Robertson was appointed honorary director of the Victorian branch of the Red Cross with the outbreak of World War II, and retired again in 1946. The year before her death in 1951 saw the publication of her autobiography/history of the Australian Red Cross Red Cross Yesterdays (1950), reflecting the way her life and work were inseparable, and demonstrating her keen observations of the human condition.
