Thank you Leandra, Suzy W and Lu - I appreciate your comments and advice. I will try the Library etc - the info I am looking for is when exactly the family arrived NZ and name of ship. They had daughter Sarah b 1853, William 1855, Mary Oliver b 1857, and Joseph b 1859. At least 2 more were born in NZ and I know about them and their families, also about Mary Oliver and her family. I haven't found correct details on any cemetery or burial records - of George and Mary Ann. I know they were born London 1827 and 1835 respectively but can only track them from their marriage in Melbourne in 1853. I will try the places you suggest, but the Aust sites haven't helped me.
Thank you again.
Kina