Prior to joining The University of Sydney's Faculty of Education and Social Work in 2003, Lesley practised social work in the fields of community health, child and family mental health and child protection. She was Director of the NSW Education Centre Against Violence, where she was responsible for the development of statewide training programs for health workers in responding to adult and child sexual assault, domestic violence and child abuse and neglect. In 2000, she established the Australian Domestic and Family Violence Clearinghouse at the University of New South Wales.