Thank you again for this information.
I found a marriage certificate for Rowland Hughes and Mary Hughes 9th October 1836 in Parish of LLandd---? Anglesey, Wales in Presence of Michael Hughes (maybe her father ?) so they should be on the 1841 Census in Wales.
I found a Rowland Hughes and Mary Hughes arriving in New York 12th August 1852 on board the ship "Underwriter" 4 months after Rowland arrived in Australia from New York without Mary. His 2nd marriage certificate states he was a widower and 1st wife died 1849 with 1 child deceased.I will see if there is any way to get this Mary Hughes death certificate to shed a bit more light on things. I have never had to get anything from America before.
I do not know anything about his siblings just names and they were all born in Anglesey, Wales.
Kind Regards Lyn