Jane Norgate was born on 30 May 1839 at Little Plumstead, Norfolk, England, the daughter of Jane Lidle and her husband, Henry Norgate, an agricultural labourer who preached in his spare time. Jane was the second daughter of five children, and had a village school education. At the age of 17 she sailed as an assisted immigrant on the Midway, which arrived in Melbourne, Australia, on 13 December 1856. She had been engaged to work for three months as a general servant for Morris Saleh, in King Street, at a salary of £25 a year. Afterwards, she worked as a domestic nurse and midwife. It was in Melbourne that she began a relationship with Henry Smith, of whom little is known except that he fathered her only child, Alice, who was born probably in 1859 or 1860. No marriage records have been found. Henry appears to have died, or left them, as he was not with Jane and Alice when they arrived in Hokitika, New Zealand, sometime around 1868.
From Hokitika Jane Norgate and Alice went to Stafford, then Greenstone, then on to Greymouth. Finally, they walked to Reefton on the survey track. After her arrival in New Zealand Jane Norgate is said to have married a man called O'Brien, but the relationship did not last; he was alleged to be violent and cruel. In Reefton Jane worked as nurse and midwife, with Alice as nursemaid. This meant that Alice had no formal education, and she was to be diffident all her life about writing. In 1872 a cottage hospital was set up in Reefton to cope with the increasing incidence of mining-related accidents and diseases, especially pneumonia, which was common during winter. On 25 November 1876 Jane was appointed the first matron. On 29 September 1879 she married the hospital chemist, David Ogilvy Preshaw, at the hospital in Reefton. They made a devoted team and built up a fine reputation for hospital care. In 1897 Duncan MacGregor, inspector of hospitals and charitable institutions, declared that 'Mr. and Mrs. Preshaw cannot be beaten as managers of such an institution'. During that year the hospital admitted 146 patients.
Jane Preshaw was a strong disciplinarian, a hard worker, skilled nurse and efficient manager. She was said to rule staff and patients (especially the rough men) with an iron hand. No patient spoke disrespectfully to a nurse in her presence. At a salary of £66 per annum in 1881, Jane earned half as much as David. In appearance she was a handsome, solid woman with an expression of confident composure. In later years she acquired a reputation for unbending severity (which her grandchildren thought undeserved).
The Preshaws remained as master and matron at the hospital until 1901, when they both resigned. After David's death on 8 June 1903 at Reefton, Jane continued with private midwifery for some years; in 1908 she helped a great-grandchild into the world. She died at Reefton on 12 December 1926 and was buried with her husband in the old suburban cemetery.