Greetings, You may have checked the IGI Batch No. C700902 for Killarney's baptisms [1819-1839], which shows these 2 children of Cornelius Mahoney & Ellen Manley: 1. MICHAEL MAHONEY- Male Christening: 27 SEP 1829 Roman Catholic, Killarney, Kerry, Ireland [refers to Vol. 6 of the Casey Collection, which might have godparents & location] 2. JAMES MAHONY - Male Christening: 14 OCT 1832 Roman Catholic, Killarney, Kerry, Ireland [Vol. 6]
There is also a CHARLES MAHONEY son of James Mahoney & Ellen Manley - Male Christening: 01 APR 1821 Roman Catholic, Killarney, Kerry, Ireland [Vol. 6]
Also, son of Cornelius Mahony & Ellen ____ [No maiden name given, but could still be yours?] a WILLIAM MAHONY - Male Christening: 28 DEC 1835 Roman Catholic, Killarney, Kerry, Ireland. [Vol. 7 Casey lists no godparents but does give the "Place" within the parish as Fussa.]
I couldn't find a marriage for Cornelius & Ellen in Killarney, using the Batch no. M700901, but there appear to be many missing for that timespan, so....
I didn't check for marriages of the above 4 male children.