Hi, Alison:
It is exciting to hear from you. Your mother-in-law must be either Margaret or Betty (nee Wilson). They were my mother's first cousins and I have photographs of them with their children when the children were very young. My mother made some trips back to Ireland and came back with photographs.
I am writing off the top of my head, no notes, so can't remember which girl married William Moore. However, the interesting thing is that it turns out that Bill Moore was a half-brother of Robert Joseph Moore, a child born to Joseph Moore and his first wife, Maggie Ross. Maggie died when RJ Moore was a child and he was raised by his mother's people, his maternal grandmother, Nancy (Gregg) Ross. Here is the connection to me. My father's maternal grandmother was Margaret Ross, sister of Robert Ross who was the father of Maggie Ross and grandfather of her little boy, RJ Moore. William Moore is a son by Joseph Moore's second wife. So I have connections to the Moores on my mother's and father's sides. It's like a jigsaw puzzle, this genealogy pursuit, and lots of fun.
Re ARTHUR, I am in the process of writing a family history and am not finished my paternal side yet. Hopefully, I will know more about the ARTHURs when I get to my mother's side. It makes sense to research both sides as they were raised in the same area. I am finding that their families intermarried several times.
John and Matilda Arthur had only one son who survived infancy, Robert John Arthur, a redhead. He came out to Canada. His wife, Betty ?) was from around Ballaghbeddy, also. They had no children so there was no male ARTHUR to carry on the name from John and Matilda's family.
I will attach a photo of the gravestone of Matilda Campbell Arthur. It was erected by her daughter, Tillie Taylor of Alberta, Canada. Annie and Robert Wilson and two of their daughters are also insciribed on this tombstone.
Colleen