Lang started her acting career in England in theatre and television, before working in her native country.
Her British appearances include Upstairs Downstairs, Crown Court, Inspector Morse, Moon and Sun, Murder in Mind, Grange Hill, Heartbeat and The Bill.
Her Australian television credits include Matlock Police, Rush Bluey, The Young Doctors, Chopper Squad, Skyways, Cop Shop, A Country Practice, Halifax f.p.
She also appeared in the miniseries The Dismissal and Vietnam (alongside Nicole Kidman), Lang's film credits Callan (1974), Don’s Party (1976), Say You Want Me (1977), A Good Thing Going (1978), The Clinic (1982) and Decadence (1994).
She won the 1977 AFI Award for Best Actress in a Supporting Role for her role in the film adaptation of Don's Party[2] and the 1980 Logie Award for Best Supporting Actress in a Miniseries/Telemovie for A Good Thing Going.