Diana was the younger of two daughters of Percy and Irene Robinson. When she was seven her parents moved to a rubber plantation in PNG, and she lived there until she was twelve. Life on the plantation is documented in a book by her sister, Penelope Hope, Long Ago is Far Away (1979). From the age of twelve Diana was a boarder at Woodlands Church of England Girls' Grammar School in Adelaide. She gained her Intermediate Certificate, then left school and studied shorthand and typing in Canberra, after which she worked as a typist in the Commonwealth Public Service. With the collapse of the rubber market in 1929 her parents left PNG, and her father managed an orange orchard in NSW. He committed suicide when Diana was 19.
In 1942 Diana married Maxwell George Mercer, an itinerant worker variously employed as a cook for cane cutters, manager of swimming baths, travelling salesman etc. Their first two daughters were born in 1943 and 1945. The family was always poor and moved from place to place about every six months from 1945 to 1951, after which they settled in Ballina. About this period Diana said, "It was sheer loneliness that drove me to writing. I had two small daughters and my husband was deeply absorbed in his work. So I began writing freelance articles and had the luck to have my first effort accepted. With the money from that article I bought a second-hand typewriter and began writing about the district and the 'how to do it' type of article for women's magazines". She took a course in journalism, and had a number of life-stories about early farming pioneers accepted by the rural newspaper Farmer and Settler.
In 1955 their third daughter was born and in the same year she and Max started a free weekly newspaper called the Ballina Pilot. Diana wrote all the articles and stories, including a science fiction serial called 'The Martian Dogs', while Max used his considerable charm to raise money from advertising. At about this time Diana renewed her acquaintance with a school friend, Enid Moodie Heddle (qv) who was at that time Education Manager for Longmans Green. With Moodie Heddle's encouragement she wrote Cows Can't Eat Cedar (1957).
From 1956 to 1958 Max and Diana collaborated with Coral Jones and Bram Schmidt to produce two craft books on making plastic flowers, belts and bags. Diana also ran a shop that sold tube plastic and tools. Diana was three months pregnant with her fourth daughter when Max was killed in a motor accident in January, 1959, but she continued to run the newspaper and also write a Ballina column for the district daily paper, the Northern Star.
In 1971 she moved to a property called "Crystal Hill" at Wardell, twelve kilometres from Ballina. She was involved with the Progress Assoc, the Camera Club and the Richmond River Historical Soc. She was passionate about the environment as early as the 1950s, and made "Crystal Hill" a wildlife and natural flora sanctuary. She was fiercely independent and constantly challenged conventional wisdom.
She was killed by a car while riding a bicycle in 1978.
