Wharetutu's date of birth is unknown. She was born probably early in the nineteenth century, for the first of her children was born in 1827. She was the youngest of the eight children of Tāhuna and Tahupare, both of Ngāi Tahu. On the side of her father, Tāhuna, she was descended through seven generations from Te Atawhiua, the brother of Rakitamau and the son of Tu-te-kawa, one of the founding ancestors of Ngāi Tahu. On her mother's side she came down five generations from Irakehu, another major Ngāi Tahu ancestor. It is not known where her family usually lived, although in 1848 her parents were listed among the kaumātua of Waikouaiti, in North Otago.
She was baptised Anne by Bishop G. A. Selwyn on 6 February 1844, and at the same time married George Newton, with whom she had already had 10 children, 9 of them still alive. As a young woman Wharetutu had gone to live with George at the sealing settlement on Whenuahou (Codfish Island), off the north-western shore of Rakiura (Stewart Island). George had been born at Kirkcaldy, Scotland, on 8 December 1803, and arrived in the Foveaux Strait region in 1827. His brother, John Newton, arrived in 1837, and lived with another Ngāi Tahu woman, Pī, who was also baptised in 1844, taking the name Mary.
When sealing declined, the Newton families and four other families of Māori wives and Pākehā husbands founded a settlement at Otaku (Murray's River), on the north coast of Rakiura. There they engaged in timber-milling for boatbuilding and local demand. When Selwyn visited in 1844, there were 28 people living in what he described as a pretty little settlement with large potato gardens. He thought the community respectable and industrious. George Newton was its leader. Wharetutu and George had 13 children. Alice Ariki died as an infant, and four others died before reaching adulthood – George, Isaac, Caroline and James.
Wharetutu's husband died on 10 August 1853 at Otaku, and the family soon became scattered throughout the Foveaux Strait settlements. Wharetutu seems to have lived at The Neck, on Rakiura, where most of the family resided. Those of her children who survived to adulthood formed the following marriages: Henry married Mata Kōtahitahi; John Mokomoko married Maria Whitelock-Chapellier; Ann Elizabeth first married Henry McCoy, and then John Pratt or Parata; Joseph married Betsy Honors; Mary married Thomas Wilson; Elizabeth married James Wybrow; Susan married Robert Ballantyne; Jacob George married Hannah Matthews or Pakana, then Margaret Coupar and finally Alice Whaitiri. Most of these marriages produced large families. Further marriages, often early in life, by the children of the second generation linked the Newton lineage with most of the other early Māori–Pākehā families in Murihiku. For example, Susan Ballantyne, the daughter of Wharetutu's daughter Susan, married Ratimira Te Au; and Mary Wilson, daughter of Wharetutu's daughter Mary, married William Lee.
Wharetutu is one of the earliest founding mothers of an extensive network of Māori–Pākehā families in southern New Zealand. She was one of the earliest of that group of Ngāi Tahu women who set up households with Pākehā men whom they eventually married. These women produced the first generation of children of mixed descent in the south. According to her descendants she died after 1870, the year in which her family were granted land at Waitai Beach, The Neck. She was buried there in the family burial ground. By 1986 her descendants numbered more than 5,000, by far the largest group of that kind yet traced.