Mary Isabella Taylor was born in Coatbridge, Lanarkshire, Scotland, on 18 June 1871, the first child of Alison (Alice) McDonald and Alexander Taylor, a railway porter. In 1877 she emigrated with her parents from Glasgow on the James N. Fleming, arriving in Dunedin, New Zealand, on 3 October. Alexander Taylor worked as a journeyman baker. For 10 years the family moved around Otago and Southland, sometimes staying a year or more in one place, but usually only a few months. Three more children were born. Alice Taylor suffered from severe alcoholism, which apparently contributed to the family's transience. She often attacked Mary physically, and when Mary was 10 threw a mug at her in anger, striking her on the head. The wound caused increasing deafness and periodic loss of sight.
The family's moves and their need for household labour and childcare frequently interrupted Mary's schooling. She first left school at the age of 12, because her mother wanted her to earn money, although she did return for a while. She was sent out to work as a 'nurse girl' to several households, and was very briefly apprenticed to a dressmaking firm; later she made envelopes and paper bags at the Mataura paper mill. When the family moved to Dunedin she began to earn a living by sewing, which became her lifelong occupation. Despite her often poor sight and the low wages, she was proud of her skill and dressmaking was the occupation of her choice. Through her work she met the Dunedin benefactor Rachel Reynolds, who later assisted her in periods of hardship.
Alice Taylor's violence continued. At the age of 16 Mary put a bundle out of the bedroom window, went off to work and did not return. She found lodgings with the help of one of her customers, and spent a happy and independent year, going to church picnics and tea parties and earning enough to live on. An attack of blindness ended her independence. She spent seven months in Dunedin Hospital, after which, still hardly able to see, she had to return to her parents' home. They had moved to Pukerau, in Southland, but soon moved again, to Waikaka, near Gore.
There Mary met Alfred (known as Alfredo) Lee, a rural labourer and part-Romany with a talent for tumbling. Soon afterwards, on 10 September 1889, they gave notice of their intention to marry at Waikaka, but the marriage never took place. Nevertheless, Mary now used the surname Lee, and the couple had two children: Alice Charlotte McDonald, born in July 1890, and John Alfred Alexander, born in October 1891. Mary Lee travelled to Dunedin for Alice's birth, and returned to find that Alfredo had leased a small coal mine in the country near Waikaka, and that they were to live on the property. Because Alfredo Lee was 'lazy' and was often away on contract work, Mary did most of the mining: she used a pick to get at the coal. There was no running water and although Mary Lee strained their drinking water, she and her daughter Alice contracted typhoid. The couple were not 'hard up', but Alfredo Lee took to drinking and gambling, leaving Mary with little income, and isolation in the country prevented her from earning her own money. After a fight in which a blow Alfredo aimed at Mary hit young Alice by mistake, Mary Lee left for Dunedin 'where i could get work – to get food'. The separation probably occurred around the time of John's birth, although evidence conflicts on this point.
Mary Lee lived at about seven different Dunedin addresses between 1891 and 1893. For some of this time she shared a house with her mother, but 'it was no uncommon thing for me, to come home from work & find that, my Bed had been taken away & my Children were Sleeping on the floor & when i got cross about it, Mother would Say Well, you wouldna ha your Mither Sleeping on the floor would ye – & i wanted twa three Shullins'. In 1895 she secured a house in Athol Place which the landlord repaired and painted for her, and she lived there for about two years.
On her return to Dunedin she had gone back to dressmaking. She obtained work from some of her previous customers, and found new ones, often among the business and professional élite of the city. The wages were low, she could not always get work, and she had children to care for. She was never able to earn enough to support her family, and until at least 1911 she received charitable aid from the Otago Benevolent Institution. Even then there was not always enough to eat and the children wore made-over cast-offs. Her ability to earn was also hampered by illness and child-bearing. She became increasingly disabled by her poor sight and deafness, and had two further children: Ernest Frederick (known as Fred) in 1895, and Kathleen Georgina Benjamin McDonald, who lived for only seven months, in 1900. There is no firm evidence concerning the fathers of these children. While Alice and Alexander Taylor were alive they lived intermittently with Mary Lee, so that her household at times included her parents and siblings as well as her own children.
As a teenager Mary Lee's daughter, Alice, began to 'run wild'. She had a son in 1906, when aged 15, and four years later married Thomas Rowe, who was probably the child's father. After Alice Rowe died of tuberculosis on 18 December 1914, Mary cared for her grandson. Mary Lee's elder son, John, drifted into petty theft and was sent to Burnham Industrial School when he was 14 years old. She saw him very infrequently for some years, and then lost contact with him until 1923, by which time John A. Lee was the Labour MP for Auckland East. Fred Lee left school to run messages and eventually bought a grocer's shop. In 1923 Mary Lee gave up her own home and lived with one or other of her sons and their families until her death at 16 Burnell Avenue, Wellington, on 7 August 1939.