She completed her secondary education at Ascham and her first year of medicine at the University of Sydney, then in 1936 studied nursing at Royal Prince Alfred Hospital.
In 1942 she enlisted in the Women's Auxiliary Australian Air Force (WAAAF) as a medical officer, being discharged in 1948 with the rank of squadron leader.
[2] In 1953, she began work in the tuberculosis ward at Callan Park Mental Hospital, but resigned the following year over the mistreatment of patients.
[3] In the mid-1970s, Waddy was a member, spokesman and later president of the NSW Doctors Reform Society and spoke out against the introduction of Medicare.
[7] She was made a Companion of the Order of Australia (AC) in the 1988 Queen's Birthday honours for "service to medical education and to the community particularly in the field of drug and alcohol abuse".