John was apparently born 2 March 1813 at Windsor, NSW, one of six children born to Thomas GREEN and Catherine McLAUGHLIN. I have very little information about him, except that

he was admitted to the Male Orphan School in Sydney after his father's death
he became a mariner
he married Sarah Bryant in Sydney on 13 October 1834
they had a child Frederick, born 25 December 1837, died 8 December 1838

After this I have lost track of John and Sarah. John Green is unfortunately a common name!