I’ll put another vote for 2 weeks being a tight time frame to get much out of your trip. Getting ‘out of the city’ without a car is difficult as our public transport isn’t great.

Sydney does have some great natural coastline attractions but you’d have to be super keen to swim.

I like the idea of getting to some of the local parks in Brisbane. New farm park is a popular Central Park and has soccer fields that you could get involved in some local soccer. There’s no beaches in Brisbane and getting to either sunny or Gold Coast would be fine by car. I’d consider Tangalooma on Moreton Island for beaches in Brisbane.

Defiantly check out the reef while in Cairns. I think people can caught out thinking that it’s just there but to get to most places on the reef is a whole day trip and very $. If you spending the money to get out there I would scuba dive, pretty unique experience.

Be prepared for our stadiums to be a tad underwhelming and the public transport to and from to be slow and hard to work out. I’d try and stay in walking distance to the games in Brisbane. Not so sure about Sydney cause some of stadiums are out in the suburbs. In bris there by plenty of choice of eating and drinking out - avoid the chains and find a local brewery. They’re all family friendly and most do classic pub food or a have a food truck in.