Hi Sharon,
You will LOVE qld!! it will be pretty hot around that time so a big change from vic weather.... I am not really sure about the northern qld islands but have a squizz on the internet and my best mate is a manager of escape travel here in QLD and she tells me that the kids clubz are AWESOME!!!
So enjoy and I hope you have a most AWESOME and relaxing holiday... sounds like you deserve it!!
Sorry if I have not answered any of your actual questions but was just excite to see someone from down south coming to enjoy QLD!!
xoxoxoxooxoxo