Daisy was born in 1863 in Tipperary, Ireland to James O'Dwyer, gentleman, and Marguarette Hunt. She migrated to Australia in 1882 marrying three times, firstly to Edwin Henry Murrant (Breaker Morant) in 1884, to Jack Bates in February 1885 to whom she had her only son Arnold in 1886, and bigamously with Ernest C Baglehole in June 1885. Jack was a cattle drover and it is believed his long periods working away led Daisy to seek companionship elsewhere. Daisy took Arnold and for seven years travelled through rural NSW working as a governess living in the homes of wealthy pastoralists.
She returned to London alone in 1894; her son being enrolled at a Catholic boarding school during her period abroad. It was during this time in London that Bates learned the craft of journalism working for the Review of Reviews as well as social campaigner W. T. Stead.
Daisy's return to Australia in 1899 is believed to have been spurred by an allegation in The Times about atrocities against Aboriginals in north-west Australia. She travelled to live at the Beagle Bay Mission where she had her first long contact with Aboriginal communities.
In 1901 Daisy accompanied her husband Jack, and their son on a visit to a cattle-station at Roebuck Plains where tribes from the Broome district were camped. Her curiosity about the camp's disputes and scandals led her to investigate their roots in kinship. Daisy began to collect vocabularies and witnessed sacred and secret ritual life. Daisy separated from Jack in 1902 having spent much of their sixteen year marriage living apart.
Bates had begun to impress the authorities with her writing prowess such that in 1904 she was appointed by the Western Australian government to research the tribes of the State. She recorded first-hand accounts of language, myth, religion and kinship, travelling widely including Perth.
In 1912 Bates established the first of the harsh, isolated camps for which she became renowned. She camped at Eucla among the remnants of the Miming tribe on the southern fringe of the Nullarbor Plain. She was invited to attend meetings in eastern capitals in 1914 of the anthropological section of the British Association for the Advancement of Science. To attend, she arranged a crossing of 400km over the southern Nullarbor Plain in a small cart pulled by camels.
Bates spent sixteen years camping at Ooldea South Australia, a permanent water-hole on the trans-Australian railway around which Aboriginals had gathered. Here she was visited by many railway travellers. Three visits by royalty brought her fame and she was appointed a C.B.E. in 1934. The Australian government gave Daisy a stipend in 1936 to prepare her papers (ninety-nine boxes in total) for the Commonwealth National Library. The sum was insufficient for normal living so she chose to do the work in a tent at Pyap on the River Murray. Her letters show that old age and failing health were at last making such an austere life untenable. Daisy died in an old people's home at Prospect South Australia in April 1951 at the age of 92.
Bates wrote 270 newspaper articles about Aboriginal life; valuably sensitive accounts of cultures customarily presented in the press as unintelligibly bizarre. Her anthropology found little favour with anthropologists and her papers lay dormant for three decades, though latterly they have received scholarly attention. Her achievements remain the subject of sustained controversy.