I searched the ROOTSIRELAND.IE database. It has abt 19 M B/M/D records for MOST of Ireland.
For Cat(herine) Considine B 1830 +/- 5 yrs, Co. Limerick, with a father named Tho(mas) and mother E(lizabeth), I found 0 B rcds.
For the marriage of Tho(mas) Considine and E(lizabeth) Birch M 1825 +/- 10 yrs, I found 0 records either in Limerick, or in all of Ireland (the portion in the database).
Note - the surnames sound Scotch-Irish and therefore likely protestant. Protestant records are the least likely to have survived at this early date. MANDATORY recording of protestant B/M/D events by churches didn't occur until 1845.