Mary Anne Arrowsmith was baptised on 19 July 1833 at Brough, Westmorland, England. She was the second of two daughters of Isabella Parkin and her husband, Henry Abel Arrowsmith, a schoolmaster. Henry emigrated to America but his family, after a few letters, heard no more of him.
Nothing is known of Mary Anne Arrowsmith's life or education before her arrival in New Zealand about 1856. She married George Frederick Swainson, a surveyor, on 27 December 1859, at the Anglican church of St James, Hutt. George was the second son of William Swainson, the distinguished naturalist, and his first wife, Mary Parkes. Mary Anne and George Swainson had two sons and three daughters, one of whom died young.
After living in Thorndon, Wellington, Mary Anne Swainson opened a school for girls on the corner of Woodward Street and Wellington Terrace (The Terrace) in 1869. She perhaps found it necessary to augment the family income, since her husband, a likeable man with artistic talent, appears to have been an alcoholic whose professional prospects had been poor for some time. His death from apoplexy in a Marton hotel on the night of 5–6 October 1870 left his widow the sole breadwinner for her children. (His estate was valued at under £600.)
A close relative of Mary Anne Swainson commented that despite her 'sad lot in life', she exhibited much 'energy under all her troubles and afflictions'. Her school soon outgrew the premises and she moved to more spacious quarters on Wellington Terrace. By 1877 these again became too small. Furthermore, the Education Act 1877, which established free education, created a threat to fee-charging private day schools. A boarding school, however, offered advantages to country parents that state schools in Wellington could not, and improved railway services were enabling more parents to send girls to boarding school in Wellington. Swainson accordingly built and in early 1878 opened a school for boarders as well as day girls on leasehold land at No 11 (later renumbered 20) Fitzherbert Terrace, Thorndon.
The school, situated in pleasant surroundings, was near the city, with accommodation at hand for visiting parents. It established a close link with the Anglican Cathedral Church of St Paul, and this attracted families who wanted a sound religious basis for their children's education. The official name was Fitzherbert Terrace School but it was usually referred to as Mrs Swainson's school.
Fees for boarders, whose numbers fluctuated between 10 and 20 over the first 20 years, were £21 per term. For day pupils they were £4 4s. Music, singing, drawing, dancing and French were extra. The core of the curriculum was religious instruction, reading, writing, arithmetic, history and geography. Girls could receive both primary and secondary education, while the few boys who attended left before reaching the secondary stage.
Dressed in black, with jet buttons reaching to the neck and her hair pulled severely back, Mary Anne Swainson presented a stern appearance. In fact she was a kind, motherly presence at the centre of the school. Although she firmly insisted on a high standard of conduct, the girls did not doubt her affection for them nor her concern for their well-being. The food was good, the domestic staff were well trained and the establishment ran smoothly under her guidance. Her excellent teaching staff included Esther Baber, a future headmistress of the school, and Robert Parker, the leading teacher of music in the city. As Mary Anne Swainson's eldest child, Mary, and a niece, Laurie Swainson, joined the teaching staff, and Isabella Arrowsmith came to live there, a family atmosphere prevailed. Emphasis was placed on good behaviour, strict attention to duty and concern for others, but in addition the pupils enjoyed parties, picnics and concerts.
In her later years Mary Anne Swainson was less involved in teaching, although she remained headmistress to the end of her life. She died at Fitzherbert Terrace on 3 August 1897, of heart failure. Her death was hastened by strain from an operation for cancer of the breast two weeks earlier.
Her daughter, Mary Swainson, became the next headmistress. The unofficial link between the school and the Anglican church was strengthened in 1920 when the diocese of Wellington acquired the school. It was renamed the Samuel Marsden Collegiate School and moved to Karori in 1926.
Mary Anne Swainson is commemorated by a stained glass window and a litany desk in Old St Paul's. As the founder of one of the country's longest established private schools for girls and one of the earliest boarding schools for girls in Wellington, she made an important contribution to New Zealand education.