Don't forget your Mary may be recorded under Farrell. I found it can be a bit hit and miss with the O, either when transcribing records or another family with the O surname was in the area. This practice seems to have extended to arrival in Australia at least in my family's case.
This is not your Mary but FamilySearch Ireland, Civil Registration Indexes, 1845-1958, records death in Scarriff 1916 of a Mary Farrell born 1843.
If you get around to chasing parish records, Scarriff or Scariff, is a town in the parish of Tomgraney, barony of Upper Tulla, co. Clare, Munster, Ireland. But to confuse things, I read somewhere that it was the main registration centre for the south-east quadrant of Clare. I found using Tomgraney helpful.
Also the LDS film note adds the Catholic parish of Scariff and Moynoe contains the civil parish of Moynoe and part of the civil parish of Tomgraney.