I posted this back in 2007, and have found some of the information on Sara since then.Some of it was what you write here.
When I first wrote, I didn't know exactly where Sarah ws born, I just assumed that she ws born in Westmeath.I was able to get a copy of their marriage record since then and have a copy of the birth records of their 5 children.It also appears that in the whole of Ireland, only one Sarah daughter of Michael seems to be extant, and that is the one you found in Tipperary.I can only assume that the Gavin family migrated to Westmeathduring some period of her youth.
I have also been able to find a death record on Sarah and Johnto conform that his father was Eugene, and hers was Michael.
John and Sarah were married in 1861, and their first child, Michael ws born in 1863.He was followed by Tim, Pat, Mary and Bridget.
The marriage recordonly told me father's names, but not mother's names. I had the same problem with my Dennehy side when my great grandfather's marriage record became available to me, it only gave his father's name, John, so I don't have the mother's name to find siblings.They were in north Cork out of Ballyhooly areathough not Westmeath! I have the same problems with both sides now. Perhaps youcomments about the records not being complete is the reason. From the records I do have, I calculate she ws born in 1836, and that is probably the correct record.I haven't a clue about Eugene, and I can'at get into my records right now, butbelieve I found a record in Griffiths that matches the cavan record you mention, but not as a birth record only, a renters.It is an uncommon enough name that I should have been able to do better, but I haven't.
I am on a laptop right now, and when my main computer wasrecently in the shop to have the hard disk replaced, I was unable to get back on the internet on that computer as it works off the main computer in the houseby antenna to themodem in that computer. For some reason, it is notcommunicating to that modem and I am not sure if the antenna is shot, or I need to wait until that computer is back and working.
One thing I do know about John Duffy though is that he has served in the Navy. When he retired he came to the US. I can't be certain about that as they we noted for telling tall tales, at least in my research.By the time my mother was an adult, all but Tim and Michael were dead, and They didn't speak to each other. In fact, my mother had been told that Michael was killed on the battleship Maine. Notso as far as I can trace.
When all computers are back home and working,I will update.