The Australia Act 1986 was assented to by the governor general and agreed to by all states so a referendum is not required.
At least thats my understanding of it.
If in fact she was charged one would think the media would have reported it, and whether she plead to it, was found innocent or guilty and the sentence revealed.
I am no gillard supporter, in fact that voice makes me cringe, but this is right wing bs that makes them look a tad silly.