Hi Christina, thank you so much for your reply, comments and information.
The information I have about the Carew/Careys and Hallys came initially from the arrival records of William Hally (known as Holley in Australia) and his wife Anne or Nancy Carew or Carey. They came to Sydney as assisted migrants and luckily quite a bit of information about their descent and origin was recorded.
It's a bit of a long story, but I found them by pure luck back in the late 1980s by dint of scanning through microfilm of shipping arrivals in Sydney in the early 1840s. The hint to look there came from William and Anne's death certificates which included information about WIlliam's parents, the names of their children, their origin (Tipperary) and the likely date they arrived in Sydney. Although the family was registered as Hurry on the immigration records, the details about parents, origin and names and ages of children allowed me to make the probable identification.
Fortunately the immigration record also included parish data - Kilfeacle for Anne/Nancy Carey/Carew and Golden for William Hally/Hurry/Holley. These records indicate that William's parents were Richard Hally and Margaret Cooney or Quinney, and that Anne's parents were Walter Carew/Carey and Judy (possibly Julie) Walsh (recorded as Welch). At the time of their emigration Richard Hally was dead and Margaret Cooney was still living in Golden, Walter Carew and Judy/Julie Walsh were still living in Kilfeacle.
Much later, as parish records became available online, I found the baptisms of William and Anne's three youngest Irish-born children in Golden: Thomas born 1n 1836, Michael born in 1838, and Honora/Norah born in 1840. I am descended from Norah. This more or less completed the confirmation that I had the right family.
The baptisms suggest a relationship with Ryans - the baptism sponsors were John Carew and Margaret Ryan in 1836 and 1838, and James Ryan and Julianne Walsh in 1840. Possibly these were aunts and uncles of the babies.
On the other hand there is the Hally name which, as you point out, is fairly common in the area. I'm in touch with a Hally genealogy group that includes Kilfeacle Hally descendants, but have yet to see how I might connect to any of the members. It's tempting to think Luke Hally might have been a brother or cousin but I don't know.
I would love to have any information that is available from gravestones, even though I suspect the family was quite poor and may not have had grave markers, so thank you for offering to search that out.
I visited the area around Golden and Kilfeacle with my husband and daughters in 2010 and got a real sense of place. We visited the church in Golden but did not visit any graveyards. Maybe we will get back again one day.
Thank you again for all your comments and information, and thank you to Ireland Reaching Out for this opportunity to connect!