[4] After winning a scholarship to a small drama school in Sydney, Millar toured Australia with a professional theatre company.
[8] Millar is best-known for playing tough, long-term inmate Marie Winter in Prisoner (1981–84), and Reverend Rosie Hoyland in Neighbours (2002–03).
[9] She has appeared in numerous Australian television dramas; among them: Hunter (1968-69), Matlock Police (1972-75), Division 4 (1973), Cop Shop (1978-80), A Country Practice (1991), and Blue Heelers (2003).
Millar won the 1976 Logie Award for Best Individual Performance by an Actress[10][5] for Homicide episode "The Life and Times of Tina Kennedy".[11].
Her experience of being an adopted child led her in adult life to take an active part in a long campaign to change the law in Australia to give adoptees access to their birth records.
She did volunteer work at a support system for young drug addicts, and she served for several years on advisory committees in NSW and Victoria with the aim of helping women experiencing difficulties with body image and ageing.