Edna Pengelly was born in Canada on 5 July 1874, the daughter of Laura Ann Brown and her husband, William Pengelly. Edna came to New Zealand as a child when her father bought a small farm at Annat, a settlement near the foothills of the Southern Alps. She walked four miles a day to attend a primary school at Waddington until one was built at Annat. For a period she also travelled daily to Christchurch West School, but was later boarded at Christchurch Girls' High School.
On finishing her education, Pengelly taught at a small private school in Rangiora. While there she lived with the Waterston family who owned the school. A Christian family, who were 'averse to drink and gambling and not afraid to avow their principles', the Waterstons had a great influence on Pengelly. After a number of years she returned to Annat, having what she called a free and easy life: attending country dances, horse-riding, playing tennis, and enjoying the company of friends.
In 1902 Pengelly and her mother moved to Levin and started a poultry farm. The work was hard and after Edna had 'splinted a rooster's leg and painted the throat of a hen which had roup', she decided 'to try to aid humanity' as a nurse. She began her training at Wellington District Hospital on 1 January 1904. The 11-hour working day started at 6 a.m., when the patients were washed and the ward prepared for the doctors' visits at 9. Other duties included scrubbing and washing soiled linen, disinfecting equipment, making beds, and checking the general cleanliness of the ward.
After completing her training in 1907, Edna Pengelly supervised various wards at Wellington District Hospital. From 1909 to 1915 she was in charge of the nurses' home, where all the probationers lived during their three years of training. The nurse in charge was responsible for enforcing the rules of the home and for fostering the value of discipline by ensuring that nurses arrived on duty on time, attended meals and maintained good health. During this period Pengelly bought a house in Wellington for £750. As her salary was £60 a year, she let the house to pay off the mortgage.
In 1915 Edna Pengelly applied to join the New Zealand Army Nursing Service. On 8 April, as a member of the first contingent of 50 army nurses, she sailed from Wellington Harbour on board the Rotorua. By June the nurses were working at military hospitals in Egypt and receiving wounded and sick soldiers from Gallipoli. The nurses found the heat very trying and the wards were 'full and fairly busy – nearly all the surgical cases being very septic – horrid gunshot wounds, and compound fractures being the most common'.
From 1915 to 1919 Pengelly served at military hospitals in Egypt and England. She was awarded the Royal Red Cross second class in 1917 and first class in 1919. Her diaries, published in 1956 as Nursing in peace and war, provide one of the few accounts of a New Zealand nurse's military experiences in the First World War. Nurses faced many difficulties as they attempted to learn the military system, and Pengelly was herself at times scathing of army structures. Her manner could be acerbic to the orderlies and the members of Voluntary Aid Detachments who failed to meet her standards. After returning to New Zealand in 1919, she was matron of the Queen Mary Military Hospital, a rehabilitation centre at Hanmer Springs, until 1921.
For the next seven years Pengelly took charge of a private hospital in Hobson Street, Wellington. She appeared to enjoy the work, finding that the owner, Dr William Young, spared no expense to make the hospital comfortable. Working in Wellington gave her the opportunity to live in her own home, to which she added a flat for her mother. From 1924 to 1928 she was president of the Wellington branch of the New Zealand Trained Nurses' Association.
In 1929 Edna Pengelly became matron of the Wanganui Collegiate School. She returned to Wellington in 1937 to be near her mother. For the next four years she supervised the dental nurse trainees at their hostel in Ghuznee Street. The trainees stood in awe of her, but they recognised her kindness and concern for their health.
Retiring from nursing in 1941, Pengelly continued to be a member of the New Zealand Registered Nurses' Association. She was also active in the National Council of Women of New Zealand and the Pioneer Club. She retained her interest in military nursing and during the Second World War assisted at the clearing hospital on Aotea Quay, Wellington.
Edna Pengelly never married. During her later years she lived in the Lady Freyberg Servicewomen's Veterans' Home. She died on 20 August 1959 at Wellington Hospital, where she had commenced her training some 55 years earlier. As one of New Zealand's most distinguished nurses, she had not only cared for the sick and wounded but contributed to the welfare of the young.