Her philanthropic activities were concentrated in Auckland, New Zealand during the first half of the 20th century.
Following a time in Kaiapoi they returned to Auckland, building "Marewa", a fine home on the north-eastern slopes of Mount Eden with gardens spreading down the hillside.
In the 1954 Queen's Birthday Honours, Blackwell was appointed a Member of the Order of the British Empire, for social welfare and philanthropic services;[2] her investiture was performed at Government House, Auckland on 25 February 1955 by the governor-general, Sir Willoughby Norrie.
The Edith Winstone Blackwell Case Room in the Owen G Glenn Building at the University of Auckland is named after her.
In 2008, the University of Auckland launched a fundraising campaign to redevelop the Leigh Marine Laboratory at Goat Island as the base for the South Pacific Centre for Marine Science - with a $4.5 million donation from the Edith Winstone Blackwell Foundation.