Born in Dunedin, New Zealand, on 23 May 1879, Elizabeth Catherine Gunn was the daughter of William Gunn and his wife, Elizabeth Jane Melton. William was an ironmonger at the time of her birth and later became a chemist and eventually a doctor of dentistry. His daughter's shared interest in teeth features in many a 'Lizzie Gunn' story from the Manawatu–Wanganui area, where she was to gain an almost legendary reputation as school doctor.
Elizabeth Gunn attended Timaru and Otago Girls' high schools. She undertook her medical intermediate year at the University of Otago, and in 1903 qualified in medicine at the University of Edinburgh with postgraduate studies in obstetrics at Dublin University. By 1908 she was working as a general practitioner in Willis Street, Wellington, where it appears that she, like a number of medical practitioners, struggled to make a living. She was not popular with other women doctors, one of whom described her loud and forthright colleague as a 'bounder'. In 1912 Gunn joined the newly formed school medical service, initially working from Wellington. The larger part of her working life was to be spent within the service, first under the Department of Education, and then, from 1921, under the Department of Health.
Gunn spent an important period from 1915 to 1917 as a captain in the New Zealand Medical Corps. This was clearly a formative stage in her life and one of which she was very proud. Gunn, in her indomitable way, virtually forced herself on the Defence Department, which was not at all anxious to have women doctors in its ranks. In 1915, the army having proved tardy in taking up her offer of help, she personally waited upon Prime Minister William Massey and complained of injury to her professional reputation. She was accepted into the Medical Corps, but was disappointed with her posting to Trentham measles hospital. However, she was credited with greatly improving the management and control of soldier patients there, and was rewarded in March 1916 with a trip to Egypt on the Tahiti. Doubts were expressed about a 'lady doctor' serving on a troop-ship, but the captain reported that everything went splendidly: 'Naturally it depends upon the lady, and Dr. Gunn, without a doubt, is possessed of unusual force of character, and is therefore an exceptional case.'
Having returned to New Zealand, Gunn was ordered in June 1916 to report to Trentham Military Camp. Here her health broke down under the strain of attending to an outbreak of pneumonia and cerebrospinal meningitis. She was given extended leave to recover from a rheumatic condition and travelled to Britain in 1917. While there she visited schools and child welfare institutions, returning to New Zealand in January 1918 with a heightened awareness of the effects of malnutrition among school children. On rejoining the school medical service, Gunn was posted to Wanganui, where her duties took her as far afield as Taumarunui and the Manawatu district.
As school doctor, Gunn cut an imposing figure. Teachers often considered her autocratic and demanding as she strode through classrooms, throwing windows open. Mothers discovered that she could be an abrasive and tactless critic of their parenting abilities, although many had great respect for her advice. Children were in awe of this dark-haired, deep-voiced woman, whose military bearing was occasionally reinforced by her wearing of war medals on school visits. She was dreaded for her practice of knocking out loose or rotting infant teeth with her spatula. In some schools the more stooped and clumsy students were dragooned into one of the doctor's 'awkward squads' to correct postural deficiencies. And in an age where bodily modesty was encouraged, developing girls were embarrassed at having to expose their immature chests for her inspection; older boys were even more horrified by her check for undescended testicles. There were reports of schools emptying of pupils when warned of her approach.
At the same time, Gunn was one of the more innovative school doctors. She was the first to formally invite parents to be present at school medical inspections and the first to introduce 'toothbrush drill' into schools. She extended medical inspection to pre-schoolers in 'Dr Gunn's Tiny Tots Parades' and encouraged the introduction of milk drinks into schools long before this was government policy. The very energy and confidence which others often found overwhelming enabled her to wear down barriers which might have deterred fainter hearts.
These qualities equipped her admirably as founder of the children's health camps movement. Having become acquainted with open-air schools and other facilities for delicate and pre-tubercular children on her 1917 visit to Britain, Gunn was convinced that she could achieve better results with less elaborate provision. The story behind the first health camp in 1919 was often told, for Gunn was a skilled publicist. Staying as the weekend guest of Wanganui Hospital and Charitable Aid Board member B. P. Lethbridge, Gunn claimed that with minimal facilities and sufficient control she could permanently improve the health of malnourished children. She and Lethbridge had a wager as to whether she could achieve her goal, with Lethbridge offering food and his Turakina farm as the site of the camp. Gunn used her considerable powers of persuasion to obtain equipment, free transport and foodstuffs from a range of government departments and local organisations. On 25 November 1919 a group of 55 children arrived at Turakina to spend some three weeks under canvas, supervised by Gunn, school nurses and trainee teachers. In this and subsequent health camps impressive weight gains were touted as evidence of Gunn's success.
Gunn continued to hold health camps at Turakina through most of the 1920s. The last camp she personally organised was at Palmerston North's Awapuni racecourse in 1930. Gunn brought her full military experience to all these camps, which were run with a firm hand by their 'commandante'. They resounded to bugle-calls, featured toothbrush drill and kit inspections, and involved a good deal of marching and flag-saluting. Her idea was eventually taken up by voluntary health camp associations all over the country, becoming institutionalised in the National Federation of Health Camps in 1936. Permanent, year-round facilities with substantial government subsidies eventually replaced the canvas camps of the pioneering period.
Although Gunn's public persona was often characterised as abrasive, health camp children sometimes glimpsed her more kindly side. Her reminiscences, written in the 1950s, portray a good-humoured practicality in her dealings with the children, a mock horror at her charges' attempts at swearing, and the judicious distribution of boiled sweets to reward good behaviour. Friends also saw behind Gunn's domineering personality numerous acts of kindness, her outfitting of needy schoolchildren with uniforms during the depression, and her ability to tell a good story and play a sharp game of cards. Although in 1935 Gunn proposed a scheme for the better training of girls in domestic occupations, she rather prided herself on her own ignorance of domestic matters: she was a regular diner at Wellington's Midland Hotel in her later years.
In 1937, following the death of the charming and conciliatory Ada Paterson, Gunn became director of the Health Department's Division of School Hygiene. Less diplomatic than Paterson, Gunn was more inclined to direct than persuade, and some of her more dogmatic pronouncements did little to foster good relations with schools or with her own subordinates. Although Gunn retired from the public service in 1940 her interest in child health did not end and she continued in practice, taking a particular interest in paediatrics. She retained a concern for 'her' schoolchildren, and remembered names many years later – even if meetings with former health campers often elicited the comment, 'You – as skinny as ever!' and a judgement, adverse or complimentary, on the appearance of their own children.
In 1951 Elizabeth Gunn was appointed an MBE. On 26 October 1963 this influential battler for child health died at Ranui rest home in Wellington. Instructions left on her death reflected exactly her ebullient personality, urging those left behind not to be mournful at her passing, as she had had a good life, and had enjoyed every minute of it.