Fanny Cohen completed her secondary education at Miss Emily Baxter’s School in Sydney in 1904, matriculating with the Kambala Prize for Women. In 1908 she graduate with a Bachelor of Arts from the University of Sydney. She followed up the following year with a Bachelor of Science and the University Medal in Geology also from the University of Sydney. In the same year 1909 she was appointed demonstrator in geology at the University of Sydney.

Whilst working as a demonstrator, in 1911 Cohen became the first woman to receive the Barker Graduate Scholarship for Applied Mathematics. The scholarship allowed her to travel to the United Kingdom, where she took up further study in mathematics at the University of Cambridge. However her studies were cut short by the ill health of her mother.

In her return to Sydney in 1912 she joined the mathematics staff at Fort Street Girls’ High School. Whilst teaching Maths, she completed a Master of Arts at the University of Sydney in 1913. After ten years at Fort Street, she left to take up an appointment as deputy headmistress of North Sydney Girls' High School in 1922. She did not stay long in this position: in 1923 she accepted the appointment of headmistress of the Maitland West Girls' High School. Threee years later in 1926, she returned to Sydney where she was appointed headmistress of St George Girls' High School. In 1929 she returned to Fort Street Girls’ as headmistress, a post she retained until retiring in 1952.

Between 1937-1952 she represented the Secondary Teachers' Association of New South Wales on the Board of Secondary School Studies.

Cohen was also involved in educational community service outside schools. She was a Fellow of the Senate of University of Sydney in the periods 1934-1944 and 1949-1959. Between 1936-1944 and 1949-1959 she served as the University Senate’s representative on the Council of Women’s College. Between 1953-1959 she was Director of the Sydney University Women's Union.

Soon after her retirement in 1952 Cohen became involved in the Royal Blind Society of New South Wales. In 1955 she obtained a braille writer's certificate and for some years translated books, helped to produce a monthly magazine for the blind, and trained other people in braille transcription.

In 1962 she was appointed a Member of the Order of the British Empire in recognition of her services to education in New South Wales.

Sources used to compile this entry: Bygott, Ursula and Cable, K. J., Pioneer Women Graduates of the University of Sydney 1881-1921, University of Sydney, Sydney, University of Sydney, Sydney, 1985; Radi, Heather (ed.), 200 Australian Women: A Redress Anthology, Women's Redress Press, Sydney, 1988, 258 pp. Also available at http://nla.gov.au/nla.arc-78644; Turney, Cliff, 'Cohen, Fanny (1887-1975)', in Australian Dictionary of Biography Online, Australian National University, 2006, http://www.adb.online.anu.edu.au/biogs/A080054b.htm.