Mary Victoria Cracroft Wilson was born at Culverden in North Canterbury on 18 August 1897, the third of five children of John Cracroft Wilson, a sheepfarmer, and his wife, Mildred Hall. Her maternal grandfather, John Hall, had been a prominent conservative politician and leader of the women’s suffrage campaign. Both he and her paternal great-grandfather, John Cracroft Wilson, had been successful pastoralists, and when the family moved to the homestead in Cashmere, Christchurch, in the early 1900s, the children had ponies, a boat on the river and were accustomed to distinguished visitors.
The family spent eight years in England, where from 1912 to 1915 Mary attended Brondesbury School in London, eventually becoming head girl. She then did three years’ nursing in the Voluntary Aid Detachment.
In 1919 Mary Wilson returned to Christchurch, where, on 24 November 1920, she married Arthur Nattle Grigg, a farmer. The couple first lived and farmed at Longbeach, his family property near Ashburton. In 1927 they sold out and purchased Surrey Hills station; here they had a new homestead built in which they reared their three children.
Mary Grigg undertook voluntary work. She first held office in the Plunket Society, becoming president of the Ashburton branch and delegate to the regional conference in 1926–27. She remained active in Plunket for another 17 years. In 1939 she was elected a founding member of the Mid-Canterbury Red Cross executive and served until 1943. She was twice a district representative at the Dominion Conference and a Red Cross representative on the Ashburton Patriotic Committee.
Arthur Grigg was elected to the House of Representatives in 1938 as the New Zealand National Party member for Mid-Canterbury, and Mary later claimed that her own interest in politics stemmed from this campaign. He left most of the running of the electorate business to her after he left New Zealand for active service in North Africa in 1940. In her own right, Mary Grigg was elected chair of the women’s division of the Canterbury branch of the party, in which capacity she became the first woman member of the party’s dominion executive.
In 1941 Mary Grigg led a deputation of representatives of women’s organisations to put the case for building a new maternity home to the Ashburton Hospital Board; she then stood for election to the board when it decided not to proceed. Her continued leadership in this controversial campaign, together with the profile she had gained in her husband’s electorate, made her popular, and she topped the county section of the poll. She was the first woman to be elected to the board, serving until her resignation in 1944. In October 1941 the Department of Education appointed her its representative to the Ashburton High School board of governors. She remained on the board for two years.
After her husband was killed in action in November 1941, Mary Grigg agreed to stand for the Mid-Canterbury seat. The first woman in the New Zealand National Party to be nominated by the electorate, when she was elected unopposed in January 1942 she became the National Party’s first woman MP and the first woman in New Zealand to represent an agricultural electorate.
In Parliament, Mary Grigg presented a woman’s perspective. In her maiden speech she not only drew on her own practical knowledge in arguing for ‘a fair price’ to farmers for increased wheat production, but also mentioned the stress women experienced at harvest, cooking for ‘big gangs of men’. She was particularly concerned to ensure that in spite of wartime shortages, reasonably priced nutritious food was available, especially to housewives on a small budget. Using a Plunket Society survey, she brought the shortage of baby clothes to the House’s notice. She endorsed women as radio announcers and jurors, urged that policewomen wear uniform and be more numerous, and sought to improve conditions for nurses. Essentially a domestic feminist, Grigg insisted that senior girls study domestic science, and also stressed the hardships women experienced in their homes. She advocated cheaper electricity, the removal of customs duty on labour-saving devices, and government subsidies for the housekeepers’ scheme run by the Women’s Division of the New Zealand Farmers’ Union.
Another key concern was the welfare of people in the armed services and the well-being of their dependants. More particularly, Mary Grigg addressed many aspects of the proposals for rehabilitating returned soldiers. She pointed out, too, the absence of any strategy for the rehabilitation of women. In September 1943 she became the parliamentary representative on the Ashburton District Rehabilitation Committee, which was responsible for safeguarding the interests of ex-servicemen and -women. Mary’s main contribution to New Zealand’s war effort was to promote the Women’s Land Service, and for this she was made an MBE in 1946. The service aimed to direct women into farm work, thus releasing men for military duty. She designed the uniform and, with Mary Dreaver, the Labour member for Waitemata, went on recruiting tours throughout the country.
On 1 July 1943, at Christchurch cathedral, Mary Grigg married William John Polson, a widower who was a sheepfarmer and MP for Stratford. There were no children of the marriage. Mary moved to rural Taranaki, and although she did not seek re-election she remained politically active. In 1945 she assisted the National candidate, Hilda Ross, in her successful election campaign for the Hamilton seat; for the 1949 National Party election manifesto both women collaborated to write the section on women’s policy. From 1952 to 1960 she resumed her committee work for Plunket. Writing in 1953, she affirmed her belief that men and women had complementary roles in public life and that ideally they should work together.
After William’s death in 1960 Mary returned to Christchurch, where she became a community leader. She served on the Dominion Council of the Girl Guides Association from 1962 to 1966, was president of the Christchurch branch of the Victoria League from 1965 to 1968, and was a member of the Karitane Baby Hospital Board, where her practicality was valued.
Throughout her career Mary had made a point of speaking out on issues directly relevant to women. While her involvement in voluntary work reflected the conventions of her class and society, by standing for public office she had broken new ground for women in her family and in her political party. She died in Christchurch on 22 December 1971. In 1977 the street in Christchurch where she lived was named Lady Polson Lane.