I have found your recent message re children.
Apart from a missing record, there are two other possibilities
Deborah was not christened as Deborah Corlett.
John Cassidy was a second marriage, the first being to a Corlett.
I did run through the potential Deborahs, but only found afew
Quayle Malew Oct 2 1797 Malew
parry 21Oct 1789 Douglas
Quirk Jan1 1788 Douglas
Gellin Nov11 1791 Douglas
Crellin June 24 1798 German
Boddagh Nov 28 1784 German
possibly one of these married a Corlett.
None had a father named Corlett.