Edith Louisa Monteath was born at Edendale, Southland, on 12 January 1890, the second of seven children of Catherine Kavanagh and her husband, Thomas Monteath, a schoolteacher. Although registered as Alice, she was known as Edith throughout her life. She attended Edendale School and on 8 June 1910 at Invercargill married Otto Ernest Niederer, a farmer. The couple were to have six children. They became dairy farmers near Nightcaps before moving back to the Invercargill district around 1919.
Edith Niederer became involved in forming branches of the Women's Division of the New Zealand Farmers' Union after attending the 1927 division conference in Wellington. When the Niederers lost their farm in the depression, Otto became a paid area organiser for the NZFU in Southland. In 1934 Otto, Edith and their three youngest children moved to Palmerston North, where Otto had been relocated by the union.
Motivated by her desire for a new economic system based on 'justice and fair dealing', Edith Niederer became a keen proponent of co-operative trading. On 7 April 1935 she was one of seven who met to establish the Manawatu Co-operative Society. Their intention was to make high-quality foodstuffs available at reasonable prices by opening co-operative stores. Edith joined the provisional committee, and was the only woman elected to the inaugural management committee on 27 September 1935. After extensive fund-raising and recruiting, the first grocery was opened on 14 November 1935, shortly followed by a butchery and other successful businesses.
It was believed that some 90 per cent of grocery purchases were made by women, so it was crucial that the co-operative movement attract women as members and consumers. Together with Marjorie MacLeod, Edith Niederer called the first meeting in October 1935 to establish a women's guild in Manawatu. At the inaugural Manawatu Co-operative Women's Guild meeting on 2 March 1936, Niederer was elected president; she stated that 'the continued success and expansion of the Movement depended mainly on the women for they had the difficult task of expending the family income'. Under her leadership, new members were recruited and monthly meetings were organised providing a mix of educational and social activities.
In August 1936 Niederer was elected president of the Dominion Council of the New Zealand Co-operative Women's Guild at its inaugural conference in Wellington. She determined that the key responsibility of the national organisation was to educate women about the social and economic principles underlying co-operation. Members were urged by her to look beyond the personal financial gains of a rebate or dividend, and to consider the wider benefits of a 'social state in which every individual had equality of opportunity'. A firm believer that 'women can be an inspiration to a home and a society', as president she had influential backing from Janet Fraser and Margaret Semple. In her time, Edith was one of the most important women in the co-operative movement.
When the Niederers moved away from Palmerston North to North Auckland in April 1939, Edith resigned her regional positions. Shortly afterwards, their son Eric went to war, and she and Otto took over from him as managers of the Nireaha co-operative store near Eketahuna. The last national guild conference Edith attended was in Palmerston North in 1943. Although co-operative retail trading succeeded greatly in Palmerston North, elsewhere in New Zealand it failed to take root. Around 1950 Edith and her husband retired to Tauranga. Otto died in February 1973, and Edith died at Tauranga five months later, on 10 July 1973, survived by four sons and two daughters.