Career
Olive was the youngest of six children born to Elizabeth Locke Mercer (*c1850) from Kirkcudbright and Sir Matthew Henry Davies (1850-1912) of Geelong, the family living at Toorak, Victoria. She was a government research scholar studying biology at Melbourne University, and wrote a paper in 1911 on Petterd"s semi-slug Cystopelta petterdi, and another in 1914 on Caryodes dufresnii, a large land mollusk native to Tasmania. On 22 December 1915 at "Cluden", in Brighton, Australia, Olive Blanche Davies married Arthur Lyle Rossiter, a lieutenant in the Australian Expeditionary Force, and elder son of Edward Lyle Rossiter of Elsternwick.
Arthur had been born in 1888 in Ballarat By the end of World War I he had risen to the rank of captain, and after the war he gave a lecture on gas warfare at Melbourne University, from which he had graduated an Master of Science . in 1911 and had been a demonstrator in physics from 1913.
He had served as a gas officer in the 4th Australian Division in France. In 1924 he was appointed on a temporary basis as senior master at Melbourne High School.