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).
Tullamain is in Co. Tipperary.
For Johan(na) Carew B 1864 (exact) in Co. Tipperary with the father's forename unknown, I found 1 rcd in Tullamain civil parish. The father's forename was Jeremiah.
Possible siblings to Johana are Margaret 1864. Note - siblings B prior to 1864 would be listed in a RC parish. I don't know what this parish is named.
For Jack Shaughnessy, there are none with this forename in the current database. Jack was usually a nickname for John. For John Shaughnessy, B 1862 +/- 4 yrs somewhere in Ireland with the father's forename unknown, I found 68 rcds with 4 in Tipperary.
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.