Nga-kahu-whero was a descendant of the great Te Rarawa leader Te Reinga, whose dwelling place was north Hokianga. Te Reinga had supreme authority over the people and land of the area and this was handed down to his son, Te Kuri. Te Kuri had a daughter, Te Ruapounamu, who had mana over land in the Waihou area, on the northern shores of the Hokianga Harbour. She married the warrior chief Tarutaru, who had mana over the land at Waireia. Their son, Kahi, inherited the mana of both parents. He married Kaimanu, daughter of Ngono, who had mana over the land at Pupuwai. Nga-kahu-whero was the daughter of Kahi and Kaimanu; she inherited all their mana, which gave her supreme authority in the area. She was also a descendant of the great woman Waimirirangi, who had a son, Tamatea, and a daughter, Pare. Pare married Te Reinga.
Nga-kahu-whero, also known as Herepaenga, was born at Waihou, in the late eighteenth century. Little is known of her childhood days. In her adult years she married Muriwhenua, who was also a descendant of Te Reinga. Just before Nga-kahu-whero was to have their first child, she went north to Whangape, accompanied by Muriwhenua, so she could give birth among her older relatives who lived there. A son named Nganiho Te Tai was born. Soon after, they returned to Hokianga, and eventually to Waihou. There, at Te Riha, Nga-kahu-whero and Muriwhenua raised Te Tai and two other children, a son, Te Hira, and a daughter, Wharo. It was also in this area that they had their gardens and plantations, where they planted kumara, taro, yams, potatoes, corn, pumpkin, melons, and peach trees.
With her inherited mana over the land and the people, Nga-kahu-whero had the authority to establish land boundaries and to give land to people, as she did to Mariao and many others. She was entitled to a share of the proceeds from sales of land made by others of the area, as when Kaumatua sold land to Bishop J. B. F. Pompallier. In all these matters no one disputed her rights. She also exercised ownership over the trees that grew on the land. Only with her permission could people fell trees in her area of Waihou; she would receive the royalties, which she kept for herself or shared with those Maori who felled the trees.
A compassionate leader of her people, she was often a refuge for those in danger of death or banishment. Kaumatua was one of those spared by her and she found a purpose for him: 'Let him light the fires to provide for those who come ashore from fishing.' She joined her people in all their activities. She went with them into battle at Waitukupahau and Te Oneroa-a-Tohe (now known as Ninety Mile Beach). She was with her people at Motukauri when Moetara and Ngati Korokoro attacked their pa in May 1833. It is said that Nga-kahu-whero threw her cloak over Moetara to prevent him from drawing his club for combat. Three years later Mohi Tawhai of Te Mahurehure established peace between the two people: Ngati Korokoro were to remain on the south side of Hokianga Harbour; Ngati Manawa and Te Rarawa would keep on the north side.
It is not known when Nga-kahu-whero died; she was buried at Papanui on Pukekowhai, together with other descendants of Te Reinga. She is held in great esteem as the matriarch of her people, Ngati Te Reinga and Te Rarawa, who treasure her memory.