Catherine Julia Bilston was born at Merino, in western Victoria, Australia, on 12 November 1864. Later known as Katrine, she was the fifth of the nine children of Ellen Augustine McElligott and her husband, George Yarra Bilston, an innkeeper who was later a grazier. Although Katrine had no formal schooling after the age of 10, at 17 she was reckoned to be 'a prodigy in literature', as by then she had published serially in the Australian Journal a novel, 'Eve's Sacrifice', and had numerous novelettes and short stories printed in the Australasian, Hamilton Spectator and Sydney Bulletin.
However, her writing career was cut short by her 'hasty marriage' on 16 September 1890 at Casterton, Victoria, to John William Mackay, a New Zealander. After the birth of their daughter, Mona Innis, in Adelaide in 1892, the Mackays moved to Whangarei, New Zealand, where a son, Cyril Augustine (known as Ian) was born in 1894. At that time John Mackay gave his occupation as auctioneer, but according to Katrine they both worked on the Mackay family fruit farm. After three years the couple moved to Auckland, and in 1900 they went to Paeroa. The rich Ōhinemuri goldmines had fostered a buoyant local economy, and John Mackay found work as an auctioneer.
After what Katrine described as 'vicissitudes', her husband deserted the family and she returned to Auckland with the children sometime after mid 1902. There she was eventually employed as a journalist for the Auckland Weekly News. She claimed to be the first woman on the staff of Wilson and Horton, who also published the New Zealand Herald. In March 1904 as 'Katrine' she began compiling the social notes. She soon rejected the notion that the social page should pander to those 'craving for a little social prominence' by crowding as many names as possible into its reports. Instead she aimed to impart interesting information in elegant language, and acquired a healthy distrust of 'limelight hunters' who showered her with invitations.
In August 1908 Mackay accepted a position on the daily New Zealand Times in Wellington, for nearly twice the pay. But, exhausted by frequent 16-hour days and the worry of paying her son's school fees in Wellington, she suffered a breakdown. She resigned in November 1909 and returned to Grafton, Auckland, where her daughter was now working for the Auckland Weekly News.
During the First World War Katrine Mackay ran a tea kiosk in Parnell, an occupation in which her childhood experience of cooking on a sheep station was put to good use. In 1919 her husband, then living in Wellington, died. She left Auckland around this time and went to Canterbury to be near her daughter. She worked as a cook for some years on several North Canterbury sheep stations, then in 1926 she settled in New Brighton and returned to journalism. For 18 months she was women's editor for the Weekly Press, during which time she compiled the immensely popular 'Cookery Chats' and 'Mutual Help Column'. After the Weekly Press ceased publication in October 1928, she published a best-selling book, Practical home cookery chats and recipes (1929).
Mackay was then engaged briefly by the New Zealand Life and Home Magazine. She continued to write on a variety of topics, using nearly 20 different pseudonyms, for a succession of journals which petered out during the early 1930s: the magazine Aussie, the Otago Witness and the Christchurch Sun. By 1935 she was in her early 70s, but still sold occasional articles, some about notable women writers. In 1929 she had begun but not finished her autobiography, 'A presswoman's memories', and in the mid 1930s she made several broadcasts on station 3YA based on this work. Her reminiscences dwell on the heavy workload and anxieties experienced by journalists and also reveal the particular difficulties encountered by women. She recalls how after evening assignments they were liable to be harassed by 'mentally afflicted persons' and sometimes even the police, as it was assumed that respectable women would not be out late at night alone. Police once mistook Mackay, who was unusually tall, for a transvestite. Nevertheless, Mackay's sense of humour shines through: for instance, she gleefully describes how once she encouraged the suspicions of a security guard while waiting to interview the prime minister, Sir Joseph Ward.
Katrine Mackay died in Christchurch on 28 March 1944. Both her children followed her into journalism; Ian became a newspaper editor at 19, and Mona was a general reporter on the Press, then a prolific free-lance journalist and author best known as Mona Tracy.