Australian Dictionary of Biography

Isabella Thomson (Isabel) Henderson (1862-1940), educationist, was born on 10 May 1862 at Ballarat, Victoria, sixth child of Presbyterian clergyman William Henderson and his wife Isabella, née Thomson. Isabel (as she was known) was educated at the then co-educational Ballarat College and passed the University of Melbourne matriculation examination in 1878. Although she 'wished passionately to be a surgeon', her father's death in 1884 made this financially impossible and she followed the traditional female path into teaching. She trained for one year as a pupil-teacher under Andrew Harper at Presbyterian Ladies' College in 1879, and taught from 1882 to 1886 at Clarendon Ladies' College, Ballarat, then until 1891 at Tintern Ladies' College, Hawthorn.

Possibly as a result of retrenchments at Tintern during the depression, in 1891 Isabel Henderson and Adelaide Garton opened a girls' school, Kalymna, in Acland Street, St Kilda. The venture prospered and they incorporated Kalymna with the long-established school, Oberwyl, in nearby Burnett Street, purchasing it in 1898. By 1906 Oberwyl was one of the largest private girls' schools in Victoria. It had an enrolment of 100 from kindergarten to matriculation, including eighteen boarders, a permanent staff of thirteen and a curriculum including Latin, Greek and mathematics, as well as the usual subjects for girls.

In 1910 Miss Henderson ended her partnership with Miss Garton at Oberwyl in order to purchase Faireleight, a private girls' school in Alma Road, East St Kilda. This school she renamed Clyde and again built up a flourishing institution. In 1919 her quest for excellence in the education of girls led her to transfer Clyde to the rural beauty of Woodend where she bought Braemar House and converted it into a boarding-school for some eighty pupils. In 1921, responding to pressures which were ending private ownership in education, she negotiated the reconstitution of her school as a corporate institution under Clyde Girls' Grammar School Ltd (later Clyde School). She retired as principal in 1924. The school amalgamated with Geelong Church of England Grammar School in 1976.

Isabel Henderson's career signals the emergence of women educators into the arena of public policy in the early 1900s, when the theory and practice of secondary education were being reshaped. She was a key member of influential educational bodies, such as the Incorporated Association of Secondary Teachers of Victoria, the Council of Public Education, the University of Melbourne Schools Board which controlled public examinations and hence school curricula, the Headmistresses' Association and the Free Kindergarten Union of Victoria. Working through these bodies she defended the rights of independent schools, especially in the areas of teacher training and curriculum development. Towards the end of her career she enthusiastically embraced the newly revived notion of education for woman's 'true' vocation—that of wife and mother. She led the campaign which saw domestic science become a subject for the Intermediate and Leaving examinations in 1917.

Tall and serene-faced, Isabel Henderson never married, and her school was her home. Her friend and colleague Olga Hay left a sympathetic account of her as a wise, warm and honest woman. For many years she suffered from diabetes, which she controlled by strict diet. She retired to England and died at South Milton, near Kingsbridge, Devon, on 29 November 1940. Her portrait by William McInnes is at Geelong Grammar School.