popsit on Family Tree Circles

Both these people came out to Australia/New Zealand some time in the 1800's.I have details on one of their sons who says he was born in Australia, Geelong, Victoria. However I have searched and someone in Australia who is more clued up than me did search also and found absolutely nothing. Four of their children came to NZ and four stayed in Australia. I have death and marriage certs for one of the sons who came to NZ. Both say he was born in the area above.I have a couple of days ago been on this site and found a lady who is researching the same people and was asking for help. I sent her a private message with my email. Her query was back in 2013.Her name is Heather Guptill. I am looking for any info on passenger lists for these people when they came over. John was a miner so he probably came to the goldfields in either country
I am looking for any children they may have had born in Ireland, any certs at all on these two. Apparently I have been told that the son(James) was born at sea. Any help really much appreciated. Thank you.