Her first novel was "The Harp in the South" (1948) – a graphic story of Irish slum life in Sydney, which has been translated into 37 languages. Even though it was acclaimed by literary critics, the book proved controversial with sections of the public due to its candour, with some newspaper letter-writers calling it a cruel fantasy because as far as they were concerned, there were no slums in Sydney. However, the newly married Park and Niland did live for a time in a Sydney slum located in the rough inner-city suburb of Surry Hills and vouched for the novel's accuracy. It has never been out of print. Sydney slum life recurs in her novel for children, "Playing Beatie Bow" (1980).