Mary Emelia Moore, the eldest of eight children, was born on 7 March 1869 at Dunedin, New Zealand, to Charles Moore, a saddler, and his wife, Mary Stewart, sister of the barrister and later MHR William Downie Stewart. Her parents were Free Church Presbyterians who encouraged their family to become active participants in the life of Knox Church, Dunedin. Mary achieved a high academic standard at Otago Girls' High School, and in 1893 she gained a BA at the University of Otago. She led a Bible class and was a member of the Otago Sunday School Union, under whose auspices she assisted in evangelistic services and provided model lessons for beginning teachers. Moore belonged to the ladies' committee of the Otago University Christian Alliance. An able speaker, she became a committee member of the Otago University Debating Society.
The religious revivalism of the 1880s and 1890s was motivating an increasing number of women to express their Christian calling as foreign missionaries, and Mary Moore developed a deep interest in the movement. She was greatly influenced by two visitors to the city: Mrs Anderson, who was recruiting for the Church of Scotland's foreign missions in China, and the American John Mott, of the World's Student Christian Federation (SCF). They enabled her to draw together two important missionary themes of the late nineteenth century: 'women's work for women', where British and American women converted those in foreign countries to Christianity; and the 'christianisation of the world in one generation', which was the slogan of the student Christian movement.
Although formal missionary training was not expected, the Church of Scotland looked for volunteers with a high level of education, leadership skills and religious training. Anderson's appeal to young New Zealand women drew seven offers and she chose three Dunedin women: E. Smith, a trained nurse, and Mary Moore and Kate Fraser, who were appointed as teachers. They were to teach and evangelise the women and children in Ichang (Yichang) district on the Yangtze Kiang (Chang Yangtze) River, China, a mission established in 1878. Supporters raised funds to outfit the women and pay for their passage. On 24 November 1896 they were farewelled by a thousand people, and set sail for Sydney on 5 December, arriving in Ichang in 1897. Mary Moore was to be based in China for 51 years.
Besides the culture shock, the struggle to learn a strange language and the lack of European female company, Mary Moore would experience years of political unrest, civil wars and anti-foreign attacks. The forts built along the Yangtze Kiang River placed Ichang under constant threat. The outbreak of the Boxer rebellion in 1900 caused the Church of Scotland to close its mission for a time, and she and her colleagues returned to New Zealand.
When Mary Moore and Kate Fraser returned to Ichang a year or so later, they opened a girls' boarding school with the funds they had raised from the sale of oriental goods while in New Zealand. They aimed to provide the girls with a trade in lacemaking and Chinese cross-stitch, and to ensure that the school was self-supporting. The scheme proved worthwhile and an industrial training school for young women was soon opened. Despite the political turmoil of the next 20 years, the number of converts grew and more women sought an education.
By 1926, however, rising Chinese nationalism placed all foreign activity at risk, and in 1927 the mission temporarily reduced staff. Mary Moore moved to a safer area on the coast. She continued with the mission until 1932, when she retired at the age of 63. Freed from regular mission work she opened her own refuge at Ichang, where she worked among the poor, blind and disabled women and children. She also began work in the men's and women's prison and formed a prisoners' aid society. The Japanese invasion of 1938 brought Moore's work to an end and she left China for the second time.
Returning to China she retired to a place known as Ching Tu. In 1940 few missionaries remained in Ichang to care for the thousand or more refugees under the mission's control, and Moore was called from retirement to give assistance. Eight years later she was evacuated to India, then to Scotland, and back to New Zealand in June 1950 aged 81. Mary Emelia Moore died 11 months later on 17 May 1951 at Dunedin. Although she had never married, she had cared for and financially supported two girls for many years; it is believed that they both emigrated to America. Her donation of more than 100 articles from China laid the foundation of a Chinese collection at the Otago Museum.