I research the Irish Family History Foundation's database. It contains 12,000,000 surviving rcds for abt 65% of Irish counties. Rcds are increasingly sparse B4 1840, rare B4 1800.
Note 1 - Without a KNOWN county, the chance of an ancestor's rcds NOT being in this database is AT LEAST 35%.
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 Owen Donovan B ???? somewhere in Co. Cork with the father's forename unknown, the earliest B rcd I found was in 1824.
For Owen Donovan M ???? ditto, the earliest M rcd I found was in 1837.
For Ellen Mullaney M ???? ditto, the earliest M rcd I found was in 1841.
For Ellen Mullaney B ???? ditto, the earliest B rcd was in 1812.
The earliest B & M rcds for Cloyne RC parish date from 1791. Note 2 may apply in both cases, although Cloyne parish was included in my search.
Sometimes microfilms of parish registers by the National Archives of Ireland, and LDS Family History Libraries copied rcds which were no longer extant when the IFHF transcribed its rcds. Suggest you try the LDS first. Its rcds are more accessible.
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.