Elizabeth Geertruida Agatha Weersma, known as Hedda, was born at Ginneken, in the Netherlands, on 15 January 1897, the daughter of Joziena Regiena van Haeften and her husband, Tiemen Weersma, an army officer. She had a traditional, religious upbringing against which she rebelled, though she developed a deep spiritual sense later in life. Hedda spent part of her childhood in the Dutch East Indies (Indonesia), later lived for nearly two years in Austria and Germany, and was in Paris studying art when the First World War broke out. She returned to Holland, and on 11 December 1918 at Gouda she married Jacobus Maria Lakeman. About this time she took up journalism and in 1919 the couple travelled via America to Surabaya, in the Dutch East Indies, where Jacobus worked in the civil service. Hedda had two children: the first, a daughter, died very young; her son was born in 1920. She divorced Jacobus Lakeman on 6 October 1923.
Hedda first came to New Zealand on assignment for a Dutch East Indies newspaper. Needing legal help because of a salary dispute, she consulted Edward Joseph Vernon Dyson, a solicitor. They married on 3 February 1927 in Auckland. Hedda brought her son from the Dutch East Indies the following year, and in 1935, her mother and a niece from Holland.
In December 1932 the New Zealand Woman's Weekly began; it had two owners in the first 15 weeks, before Vernon Dyson bought the magazine and Hedda became the second editor. For some time the future of the Woman's Weekly remained shaky: Hedda typed virtually the whole magazine and – as she and her husband could not afford to buy articles – wrote most of the contents. The Dysons were delighted when New Zealand Newspapers took over ownership at the end of 1933, retaining Hedda's services.
The Woman's Weekly included 'social notes', short fiction, and articles on cookery, fashion, royalty and Hollywood stars, but Hedda Dyson wanted to offer her readers something more. In her editorials she regularly commented on social and political issues, stating that 'it is the duty of a family magazine to bring many facts to the fore…Our policy is to discuss matters openly and give readers the opportunity to judge for themselves.' She read voraciously, and her keen interest in philosophy, psychology and current affairs and fluency in several European languages helped shape her outlook. She was also interested in people and constantly sought out their opinions.
Editorials frequently contained analyses of international issues such as world peace, the rise of fascism, and life in the Soviet Union. Concerned at the level of ignorance in New Zealand about these matters, Dyson urged women to study world affairs and in the late 1930s helped set up educational groups. National politics were also explored; after the 1935 election she visited Wellington to interview the wives of Labour MPs, and in 1947, with strikes and the fear of communism increasing, she wrote about the New Zealand Federation of Labour and later ran interviews with watersiders and prominent unionists. She did not hesitate to speak out, criticising for instance powers conferred by child welfare legislation, and a Wellington women's group which voted to introduce flogging for sex crimes. She deplored the Labour government's control of radio, especially during the Second World War.
Dyson did not neglect to comment on everyday difficulties: women's search for work, the cost and quality of household goods, home management, and the difficulty of obtaining domestic help. She declared herself to be 'a feminist in heart and soul'. It was her belief that the housewife 'should have time to read, to learn, to act on committees, attend meetings and, once her children are past the tiny-tot stage, to do outside work if she wishes.' She was a firm supporter of equal pay and rights for women.
From her first issue of the Woman's Weekly Dyson urged women to join social service organisations so they could contribute to the well-being of the state and help safeguard their children's future. She herself set an example: in 1937 she represented the New Women's Club (of which she was a founding member) to make a submission to the Committee of Inquiry into Maternity Services urging free maternity care and adequate pain relief in childbirth. During the Second World War a regular page in the Woman's Weekly described and encouraged women's war work and organisations.
Having established a high profile with women's clubs and associations in the North Island, Dyson in November 1935 began presenting an hour-long weekly radio variety programme, broadcast on 1ZM Manurewa. It consisted of 'bright and informative "shorts" ', including her own one-act plays. Her personal following was evident in the number of letters she received from listeners.
Readers' contributions were an important aspect of the Woman's Weekly during Dyson's editorship. The fiction section usually included two serials and at least one short story, and New Zealand writers were encouraged. Stories, short paragraphs, hints and letters from readers all received payment. Another distinctive feature of the magazine was its news of champion sportswomen, and the growth of women's sports such as cricket, tennis, hockey and basketball. Always keen on fitness herself, Dyson joined the women's rowing section of the West End Rowing Club at Freemans Bay, and in 1935 took part in the New Zealand women's championship in Wanganui.
An attractive fair-haired woman who took care with her appearance, Hedda Dyson was as interested in fashion as she was in politics, and in the late 1930s the Woman's Weekly ran a Miss New Zealand contest. In 1938 Hedda herself won a worldwide competition for women over 35, organised by an American health and beauty magazine. The prize was a short tour of the United States. She stayed a year, during which she argued with an American socialist party leader over his neutral stance on Nazi aggression in Europe, made a radio broadcast, and – 'the greatest adventure of my life' – met Eleanor Roosevelt. This was the last of several trips. On her return, she published a series of articles based on her travel diary.
Dyson remained editor of the New Zealand Woman's Weekly until the end of 1948. Industrious to the last, she used a period of hospital treatment and convalescence that year to write critically about the health system, suggesting greater emphasis on prevention.
Throughout her editorship, the all-woman editorial and office staff of the Woman's Weekly remained very small. However, the magazine increased its circulation rapidly, from 22,447 in 1934 to 32,202 by the end of the decade, reaching 67,663 by 1948.
After retiring, with a partner Dyson set up a printing business in Warkworth, where she and her husband owned a farm. The business was not a success. From November 1949 she was briefly director of the Happiness Club. By then her heavy smoking habit was taking its toll, and she and Vernon had separated. She died of cancer in Auckland on 17 October 1951. Hedda Dyson was remembered for her 'enthusiasm and enquiring mind [which] had led her into so many activities, and had brought her in close touch with so many people.'