I see that Margaret was aged 86 when she died and that her residence was Ballyboy. Her son, John was the informant and present at her death. I believe that Margaret and John were listed in the 1911 Census in Moynoe townland. Ballyboy may have been a place name associated with Moynoe. I can check this out with a Moynoe farmer :)
I also see that John Nelson married Helena Walsh in 1918 in Scarriff and that he was a son of John Nelson. I have attached the link to the civil marriage record:
John Nelson died in 1944 aged 75 and his wife Helena was his informant. Here is the civil death record:
I will ask a local person about the family as I don't see any headstone in Moynoe graveyard for them.
I'll reply back when I have further information.
All the best,