The word "shiralee" is Australian slang for a swagman's blanket roll or burden he carries with him. Here's it's used to refer to the kid.
Both of the feature films set and filmed in Australia, and starring actor Peter Finch - ''The Shiralee" (1957) and Robbery Under Arms (1957), have been remade by the South Australian Film Corporation (See: The Shiralee (1987) and Robbery Under Arms (1985)).
Opening credits: The events and characters portrayed in this film are fictitious.