Clearly it is not a Southern (Common) Brown Tree Frog as these are only naturally found as far north as Ulladulla in NSW (200 km+ south of Sydney). There are five possible candidates (that I am aware of) in your area…
1. Litoria brevipalmata Green-thighed Frog
2. Litoria dentata Bleating Tree Frog
3. Litoria latopalmata Broad-palmed Frog
4. Litoria verreauxi Verreaux's Tree Frog
5. Litoria wilcoxi Stoney Creek Frog
It is too early to call it with any certainty for someone like myself, who is not familiar with the tadpoles or morphlings of these species. Having said that, if I were a betting man, I would put my money on Litoria verreauxi. Time will tell.