I research the Irish Family History Foundation's database. It contains 12,800,000 surviving rcds for abt 70% of Irish counties. Rcds are increasingly sparse B4 1840, rare B4 1800. Cos. Donegal and Derry were recently added to the database.
Note 1 - Without a KNOWN county, the chance of an ancestor's rcds NOT being in this database is AT LEAST 30%.
Note 2 - Only 1/2 of Co. Cork's rcds are in this database.
Note 3 - The RC church kept control over most parish rcds from Tipperary (north). These are ONLY available thru the Tipperary Family History Research center at a substantial fee (regardless of outcome).
For Martin Killalea B 1825, Co. Galway, with the father's forename unknown, the earliest rcd is 1832. The LDS, or National Library of Ireland may have microfilms of earlier rcds.
For Honor Ford B 1830 +/- 4 yrs, ditto, I found 6 rcds: 1826, 1828, 2-1831, 1832, and 1834. Father's forenames were Daniel, Thomas, Joseph, Thomas, Thomas, and Timothy respectively. Will leave it to you to find the parishes.
You will need an exact DOB, parent(s) name(s), and/or placename(s) to pick which, if any, rcd is for your ancestor. Suggest you try the RC church in Cincinnati to find their M rcd. The M rcd often lists the parents' names and sometimes origins.
Google the Foundation's name to lead you to this database. Register, opt to be notified as rcds are added and browse. Pls post your search results to my genforum msg.