Hi KathBMC
I've spent a bit of time trying to figure out if you are indeed related to Mary. Her great great grandfather is very very likely to have been the John Bradley, a tenant farmer on this 30 acre farm in 1858. The Cassidys now own this land. In addition to John Bradley, only two other families with the name Bradley lived in the townland of the Erganagh at this time. One was Dominick Bradley, the other was a William Bradley who must have been your ancestor. It may be that these Bradleys were related to one another, perhaps brothers. Unfortunately, despite my research I couldn't prove this.
I now know for sure where William Bradley lived in 1858. This dwelling was only wallsteads until recently when the farmer removed the remaining structure and returned this to farmland. This particular old dwelling was known as 'Kittys'. In an earlier message I suggested that this lady may have been Kitty Convery. This is incorrect. The lady who once lived here was called Kitty Crilly.
Should you or your family decide to come for a visit, I would be more than happy to show you the site where William Bradley had his farm in 1858.
A few years ago, my brother was contacted by a gentleman in Canada of the same name who wanted to find out if they were related. They both decided to undergo the new DNA test. This cost a few hundred pounds but did indeed prove beyond doubt they were related. I suspect that for you to prove a relationship beyond doubt with Mary Cassidy, this DNA test may be the only foolproof way because the local Roman Catholic Church was burned in the early 1800's destroying most, if not all, birth marriage and death records. The burning of the Four Courts in Dublin during the Civil War destroyed these records also. This is why genealogy in the Kilrea area (in the R.C. population) is so difficult.
Bill