Emma Hilda Keane was born in Auckland, New Zealand, on 18 May 1873, the eldest of six children of Elizabeth Hancock and her husband, Henry Keane, a hotel-keeper. The family moved to Christchurch, probably in the late 1870s, and Hilda attended Christchurch West School and Christchurch Girls' High School. By 1894 Keane was living in Auckland, where she attended Auckland University College. She was a member of the drama club and the Girls' Korero Club, which she helped found in the late 1890s to encourage debating and writing. A short-lived teaching career included a year (1901) as a governess at St Hilda's Collegiate School in Dunedin, where she also attended lectures at the University of Otago.
Returning to Auckland, she was engaged in April 1902 to assist in editing the New Zealand Illustrated Magazine and to write its women's pages. She also contributed theatrical reviews, stories and poems under various pseudonyms. She remained with the magazine until its demise in 1905.
From 1899 Keane had regularly written articles for the New Zealand Herald supplement and for the Auckland Weekly News. In 1903 she investigated and wrote about the poor conditions in inner city housing; her reports led to improvements. Other series covered domestic servants (to write which she took positions in several homes), women in prison, normal schools and other community institutions. She also contributed to the major papers in Wellington, Dunedin and Christchurch.
On 20 August 1902, at Auckland, Hilda Keane married Frederick Carr Rollett, the agricultural editor of the Auckland Weekly News; she continued to use her maiden name for writing. They lived for some years on an orchard in Henderson, and she often wrote about the value of a productive life for women on small holdings compared to the emptiness of conventional social life in the city. 'Make yourselves independent, and try to be all-round useful women', she advised.
Despite her highly successful career as a journalist, Rollett believed that women's home duties came first. She was ambivalent about domestic service as an occupation for women, and believed that the development of labour-saving devices allowed women to manage their own homes, as she did herself for many years. As a former teacher, however, she believed firmly in the value of education for women. In 1902 she took up the cause of education for Maori women through the Illustrated Magazine's pages, and encouraged her readers to contribute money or books to the newly established Queen Victoria School for Maori Girls.
Hilda Rollett became a prolific contributor to overseas journals, and was the New Zealand correspondent for the New York Sun. She wrote on politics and economics as correspondent on imperial matters to Britannia for 10 years, and was monthly correspondent to the Sphere, as well as contributing to the National Review, the Empire Review and Macmillan's Magazine.
Rollett also wrote fiction, which was published in English periodicals, in the New York Sun, and in Australian journals including the Bulletin. A highlight of her career was winning one of the top places in the first overseas literary competition held by the Lyceum Club of London in 1905. She had joined the club in 1904 and was its New Zealand representative, responsible for vetting local women's manuscripts intended for its London agent. Later, Rollett ran the literary circle of the Auckland Women's Club (renamed the Auckland Lyceum Club in 1922). In 1925 she was one of the two founding vice presidents of the League of New Zealand Penwomen, which provided encouragement to many women writers, artists and journalists. She was later president for several years. By the early 1940s she was the New Zealand representative for All about Books, published in Melbourne, and she occasionally judged literary competitions.
Hilda Rollett's skill as an artist – she was taught at one time by C. F. Goldie – led to her work as art critic for the New Zealand Herald and the Auckland Weekly News. As 'Critic' in the Herald, she reviewed current literature for some years, and also contributed to other metropolitan dailies. In 1925 she collected some of her articles into a book, A pleasant land.
In 1910–11 Hilda Rollett had travelled to England with her husband and other press representatives on the occasion of the coronation of King George V. Her reputation earned her a warm welcome from the Empire Press Union and the Institute of Journalists, London, and she was elected to both bodies. The Rolletts also travelled to Fiji to undertake a survey of development prospects.
Rollett served on various community organisations such as kindergartens, the Auckland Technical College Board, and the Auckland branch of the National Council of Women of New Zealand. She became the first honorary secretary and vice president of the Auckland branch of the Victoria League, helping to organise its Red Cross committee early in the First World War as well as approaching the Auckland Provincial Patriotic and War Relief Association to set up a soldiers' club. In the early 1920s she worked with the Plunket Society in their 'Save the Babies' campaign.
Hilda Rollett's children, Elizabeth and Wilfred, born in 1916 and 1917, were still in their teens when their father died in 1931, aged 70. A good manager, Hilda kept the family and the house on interest from her savings and the money Frederick left them, while his former employer, the New Zealand Herald, paid for Wilfred's education. She continued to contribute to its supplement until about 1938. She was remarkably successful as a freelance journalist, earning between £200 and £250 in her regular working years – more than the average wage of a newspaper reporter in the early 1930s.
Hilda Rollett continued to live in Auckland, where she died on 2 April 1970, aged 96; she was survived by her two children.