A Baptist deaconess for thirty years, she was president of the Dunedin chapter of the Women's Christian Temperance Union New Zealand (WCTU NZ) from 1916 to 1955, and meanwhile served as vice-president at the national level from 1926 to 1934 and again between 1946 and 1949.

Her parents had married in 1868 in New Zealand and lived in a small fishing village southwest of Dunedin in Otago, Taieri Beach,[1] where they owned a store and a farm.

[3] She led services for the Young Ladies' Bible Class, participated in the Charitable Aid Board, and supported the temperance efforts of the "No License Association".

[6] Hiett organised an Otago District Convention in 1923 that produced resolution and petitions in line with WCTU NZ goals: scientific temperance instruction in public schools, remove political disabilities of women (especially the role of Justice of the Peace, serving on juries, becoming a member of the police force).

[8] This loss must have galvanised Hiett who then at the Otago District Convention in October 1925 gave a strong speech for national Prohibition as a crucial step in human progress.

[12] Besides his role as a singer in the Hanover Street Baptist Sunday School, William Henry Hiett had been an active supporter of the temperance movement, leading children's groups called Bands of Hope.

[15] As the war in Europe and the Pacific theatres heated up, she advocated for total abstinence since the liquor industry encouraged waste and used the grain needed for starving people and animals.

[16] On 13 November 1940, the Hanover Street Baptist Church in Dunedin honored Hiett for her 25th year of service as deaconess, and they presented her with a "fireside chair.

[20] In 1945 at the WCTU NZ convention at Dunedin the debates over the Union's stance on conscientious objectors showed the conservative turn most delegates were beginning to evidence.

[21] However, Hiett continued to push for closing saloons when all wished to celebrate the end of World War II, e.g., Victory in Europe Day.

"[25] In early 1946, their brother Donald McKenzie, a boat builder who also lived together with them at 11 Duke Street in Dunedin grew ill.[26] He was 75 years old when he died on 24 March 1946.

A description of her leadership skills was published in The White Ribbon: Hiett served as Dominion Vice President under Cybele Ethyl Kirk of Wellington from 1946 to 1949.