Professor Barnett is a child and family psychiatrist with a particular interest in early intervention, perinatal and early childhood mental health. Her doctoral thesis studied anxiety and its effects on mothers and their infants.
This research included the first attachment study in Australia. Professor Barnett holds a conjoint professorial appointment with the School of Psychiatry at the UNSW. She is also a foundation member and past President of the Australian Association for Infant Mental Health, the Australian Society for Psychosocial Obstetrics and Gynaecology, and both the International and Australasian Marcé Societies. In 2007 she was awarded Membership of the Order of Australia in recognition of her service to families and the profession. In 2016 she received a RANZCP College Citation.