Hi,
To add to your long shot a pension application in 1908 gives a family of Keegans in Ballyhagan, parish of Kilmore, Co. Armagh in 1851 taken from the census.
John Keegan Father
Mary Keegan Mother Maiden name not known but there were two Toner households in this parish in 1864
Elizabeth aged 7
William aged 5
Jane aged 1
John under 1
Regards