Some Other Sources for Free things to do with Kids
I would like to direct you to the following website for a great list of things that you can do for free in the city of Melbourne.
Here is the link for free stuff to do with kids!
This is quite brief and doesn't give a detailed account of each place, but it does give some ideas. You might want to search the site for some other cool things to do too!
While I'm at it, here is another place you might want to go to find free stuff to do.
This one has a bigger description, but not as many nice pics! The page is a bit busier too, which might be a little off-putting.