Have you tried the Irish Civil Registration Index at
www.familysearch.org for the marriage of Mary Callanan and John Neill?
There is an entry in 1878 Carrick on Suir Registration District Quarter Jan- Mar Vol 4 page 594 for a marriage of a Mary Callanan with a match for a John O Neale that might be a possibility.
The cert would give John O Neale's residence at marriage and his father's name that may give some further clues. You can get an order form online at
www.groireland.ie (photocopies give the same information and cost less) if you wish to follow this up.
I couldn't find them in the 1901 Irish census - did they leave Ireland?
Hope this is of use
annclare
