There's a baptism of a Dennis Carr showing up on the free index of Co. Kildare records on RootsIreland sometime between 1820-1824, however it doesn't appear to be in Athy (either RC or Church of Ireland records).
You have to pay to view the transcript, but it might be worth following up...
(an RC baptism record from this timeframe will probably show date of baptism, names for both parents, and possibly names of two godparents)
Shane