Ok,...thank you!
I notice William John marries in Australia aged 24,......I was thinking 'transportation', but that seems awfully young to have already served a setence and be free to marry. I will check into that, as I'm not sure how commonplace voluntary emmigration to Australia was!
update: William John marries Isabelle Cairns Bell in Charters Town , Queensland 1887.
Quick search shows that it was a booming gold rush town settlement, in those days....interesting story beckons!