If Andrew was the son of my GGGgrandmother he was left behind because he was over 8 years of age when she was transported. She was listed as a widow and took 1 son (apparently under 8) and 2 daughters (apparently under 12) when she left in 1835.
Perhaps he married at BaBallaugh because his guardian lived in that district. He may have set up in business sometime later.
The reason for my following this lead is to try to find details about his parents who like Andrew appear to have been born in Ireland.
Sarah, the mother, is listed on a County Down list of transported convicts born in Down.
Cheers
Peter
Melbourne