 Gillham then moved to work as a Senior Demonstrator at the Department of Botany at University of Melbourne, Australia on 3 March 1958 during an exchange lectureship.From 1961 to 1988, she lectured at the Adult Education Department at the University of Wales, Cardiff, until her retirement in 1988.In 1963, Gillham worked as a Staff Tutor in the Biological Sciences at University College of South Wales and Monmouthshire, Department of Extramural Studies.