Mary Elizabeth Waine, the daughter of Mary Craddock and her husband, William Waine, a baker, was born in Aldsworth, Gloucestershire, England, probably on 10 January 1836. She was baptised there a week later. The family later moved to St James's Square, Notting Hill, London, where Mary met James Gibbs, whom she married on 16 December 1858. By 1866 James was a registrar at Somerset House. In 1876 the Gibbs and Waine families owned three adjoining houses in St James's Square; Mary and James Gibbs, their five sons and four daughters occupied two of these.
By the late 1870s Mary Gibbs's health was causing concern. Friends in Nelson, New Zealand, wrote of the healthy climate, and the advantages and prospects of their colonial life, extolling the virtues of the Bishop's School and Nelson College. As the Gibbses could not afford an English education for their family, they decided to emigrate. They planned to farm, and to prepare for their rural life, Richard, the eldest son, attended courses in technical subjects, offered by the Department of Science and Art in South Kensington, in order to learn the use of agricultural machinery. Travel arrangements had been made when James Gibbs died. However, Mary decided to proceed as planned. The family sailed on the Queen Bee on 21 April 1877 from the East India Docks. Around midnight on 6–7 August the ship ran aground on Farewell Spit, at the northern tip of the South Island. The Gibbs family were taken off, divided between the two ships' boats under jury-rigged blanket sails; they were reunited unharmed in Nelson.
Mary Gibbs had taken out only a small insurance policy, and as an economy measure had shipped most of her luggage, furniture and chattels as freight. When the salvaged freight was sold by auction, she bid for her possessions. Some less charitable Nelsonians, believing her well-to-do, bid against her and she was unable to secure some of the better pieces.
For three weeks Mary Gibbs and her large family lived at the Custom House Hotel. She intended to purchase land, but was advised by the manager of the Bank of New Zealand to invest her money in a home in Nelson and spend the balance on her children's education. She purchased a house in Nile Street, within walking distance of schools and colleges.
The surrounding countryside encouraged the family into outdoor activities, and while her health allowed, Mary Gibbs joined in wholeheartedly. She organised many social activities such as picnics, boating and tennis, and was much involved in charitable work. She became vice president of a debating society at Nelson College for Girls in 1891; one of the topics of debate was women's franchise. Mary Gibbs was also believed to have been one of the first women members of a school committee. She was a well-known figure walking around Nelson in an ankle-length taffeta gown and lace cap. A strong-minded woman, she disagreed with the sermon preached on her first visit to a church in Nelson and never returned, but she regularly attended a neighbouring church.
The family was interested in music, attending harmonic society concerts, holding musical evenings in their home and organising a musical evening society. The children were encouraged to hear visiting lecturers and to read worthwhile books. It was, perhaps, these interests that led Frederick to suffer intense loneliness when he was out of the family group – most New Zealand boys were unaware of the things the Gibbs family appreciated.
Mary Gibbs's determination that her family should succeed was handsomely rewarded. Richard became a banker. Frederick, a university graduate who had attended Canterbury College, was a local schoolmaster. The three other sons graduated in medicine from the University of Edinburgh, and two daughters married sons of well-known Nelson families.
In 1905 Mary Gibbs moved from her Nile Street home to live with Frederick, who was unmarried; she was cared for by her two unmarried daughters, Resa and Nell. She died at Nelson on 21 October 1920.