I think I have responded to another of your posts. Your name looks familiar. Hope this info isn't redundant.
I research the Irish Family History Foundation's database. It contains 12,700,000 surviving rcds for abt 72% of Irish counties. Rcds are increasingly sparse B4 1840, rare B4 1800. Co Donegal rcds were added to this database July 7, 2009.
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 Mary Anderson B ???? somewhere in Ireland with a father forenamed Robert, the earliest rcd I found in Co. Armagh was in 1892. For all other counties in the database, the closest in time are a rcd in 1816 Antrim, and 1846 Donegal. These aren't likely to be for this ancestor. The highest probability is that the rcd of this event didn't survive.
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.