Using some of the information already on this thread I did a bit more digging. I might have sorted out the O'Briens a bit more but it might get even more confusing from her on Now for some new details. I looked in 1911 for Mary O'Brien, widow, aged about 55, in Waterford and found this one in household of a son-in-law. Her daughter was Bridget and son-in-law William Long! Mary's age is off from 1901 which isn't uncommon.https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1910/09985/5631572.pdf (his father Thomas Long! and her father James O'Brien with a James O'Brien as witness)