I searched the Roots Ireland indexes. The RC church would have been Castletownroche. I located three baptismal records with parents James and Isabel. They were Mary in 1815, Thomas 1817 and Johanna 1821. I did not find Catherine. The records for Castletownroche start in 1810 according to Roots.
There were three other records in Castletownroche where the father was James however the mother was not Isabel or Bella.
Later this summer the National Library of Ireland plans to place all RC parish registers online for free searching. I would look at the Castletowroche records at that time.