Some great birding areas where you are heading. Was there in January and did exactly the same as you, whilst also visiting my partners family.
Brisbane/Gold Coast - Mt Tambourine, O'rilleys rainforest, Lammington National Park,
Further south - Port Mcquire
Sydney - Blue mountains, Wollemi national park
Melbourne - Phillip Island
If You Have Seen One Ant, One Bird, One Tree, It Doesnt Mean You've Seen Them All