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Fortunately records for Tawnagh/Riverstown RC parish go back to 1803. I searched the subscription site Roots Ireland and located an 1821 Catherine Kerin baptismal record in Riverstown. See below.There was also an 1818 and 1825 Catherine Kerin baptismal records. I did not find a record for Thady (or a name close to Thady like Timothy) from 1809-1819 in Riverstown.
The 1857 Griffiths Valuation head of household listing for Emlaghfad civil parish shows a Thaddeus Tighe in Rathdoony More townland likely your ancestor.
Let me know if you need additional info.
Name:Catherina KerinDate of Birth:
Date of Baptism:10-Dec-1821Address:
Sponsor 1 /
Informant 1:Patrick KrineSponsor 2 /
Informant 2:Maria Brennan