[4] In April 1941, Drummond joined the Women's Royal Naval Service (WRNS) and served as a writer (equivalent in rank to able seaman).
[5] She was promoted to second officer (equivalent to lieutenant) in October 1942, with seniority from 29 August 1942,[6] and in early 1944 joined the staff of Commander-in-Chief, Plymouth.
[2] She was "responsible for the administration and paperwork relating to the command's role in operation Neptune":[2] as such, she was the first woman to learn about the Normandy landings.
[2] Then, with promotion to superintendent (equivalent to captain), she joined the staff of Commander-in-Chief, East Indies Fleet.
[2][10] Drummond was appointed an Honorary Aide-de-Camp to Queen Elizabeth II on 4 June 1964,[10] and a Dame Commander of the Order of the British Empire in the 1965 New Year Honours.