Hi Sue & everyone
As a result of all your help I have solved the riddle of James Crocker, just a few points to sort out.
2 x great grand parents
James Crocker - B 1834 Gwennap, Cornwall, England - D 1894, St Kilda, Victoria
Isabella Hogg - B 1844 (location unknown) - D 1873, St Kilda, Victoria
Both of James parents died before he was 17, both he and his elder brother William worked in the mines in Cornwall. I have found a record of his younger sister Eliza coming to Australia as a single female in 1858 but I haven't been able to find a manifest for James yet. It would have most likely between during the 1850's as he married Elizabeth Hogg in 1864.
They were married in Maryborough, Victoria on the 18 March and their children were either born in Maryborough or Chinaman's Flat. They would have been there at the height of the gold rush. Two of the children are buried in the Timor Cemetery.
3 x great grandparents
William Crocker - B 1811 Gwennap, Cornwall, England - D 1846 Gwennap, Cornwall, England
Sarah Richards - 1810 Gwennap, Cornwall, England - D 1849 Gwennap, Cornwall, England
Married 2 Jun 1831 Gwennap, Cornwall, England
It appears as if Sarah's mother Sarah Prisk may have been living with or next door to her grandchildren following her daughters and son-in-law deaths. Shown on the 1851 census.
I have had no luck on the Isabella Hogg side other than her fathers name is George. Oh I did get a copy of the Birth Certificate which was helpful but as is the case so many times the hand writing was dreadful so I could not find out where Isabella was born.
I believe I read a post from someone that mentioned twins and it does appear as if James had twin sisters than unfortunately died aged 2 years.
Thank you again for everyone's help, back to work on the Hogg side and then onto my grandmother Dorothy May McGlinn another one I can find no record prior to marrying my grandfather.
Happy digging!
Chucky