Great advice from mungomuffit.
I'm an Aussie girl too - opposite to mungomuffit, my family lives in the south - Sutherland Shire - and I decamped to Glebe/Newtown ASAP too!
Beaches are good in "The Shire" and it is very family friendly but the commute to the city is about an hour from areas like Jannali and then the closer you get to the beach, the more like 1 hour 20-odd.
Everywhere is expensive though.
If we were going to move back to Sydney, my husband wants to be near a beach and walking distance to a pub.
That means, I think, Eastern Suburbs and at least a million Aussie dollars on the house. And a bus commute for him to the CBD.
Most people assume a minimum hour commute in Sydney - the distance is quite vast. Lots of people drive too.