Gerard,
Thanks for that; the family at House number 15 is the Brennan family that i'm working on, so Brennan's at House number 14 would make sense.
Might be a few difficulties with the margaret from the census being the one that i'm looking for; the way i read the household record is that Charles O'Brien is the head of the house; Margaret O'Brien is his wife; Thomas Brennan is Margaret O'Brien's brother and he happened to marry another Margaret, making Thomas and Margaret Brennan Charles O'Brien's brother and sister in law. So, that means that both Margarets are already married and there's no sign of a Kilfeather.
Working from what i know, Margaret O'Brien would have been from the generation before the margaret that i'm looking for.
However, the marriage for James Kilfeather and Margaret Brennan makes sense, but i wonder where she was for the census? Unless she was away from Finglas for work.
C