Hi Marion
Welcome to Ireland Reaching Out!
If you take out a day subscription to rootsireland.ie you can locate a transcription of Thomas' baptism for above mentioned date. William and Mary married in April 1844 and other children included Honor, Patrick, John, Edmund, Catherine and a 2nd daughter named Honor as the first likely died - I couldn't find a death record for her though that is not surprising.
There is a likely Griffith's Valuation record HERE
Thomas' digitised baptism record is available HERE and you can also search that site (registers.nli.ie) for his siblings digitised originals as they are nice to see in that format. That NLI site is free.
Best wishes
Clare Doyle
Genealogy Support