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 Teresa O'Kane B 1898 +/- 1 yr, Co. Antrim, with the father's forename unknown, I found 2 rcds: both 1897. One for a Teresa, the other for a Theresa. Father's forenames were both James. A view of the detailed rcd SHOULD show the mother's name.
For K(athleen) O'Kane B 1898 +/- 5 yrs, Co. Antrim, with a father forenamed James, I found 1 rcd for a Kathleen, 1896. Ditto
For James O'Kane M 1890 +/- 5 yrs, Co. Antrim, I found 20 rcds - too many to easily summarize here. Use the mother's name to help pick which, if any, is the right one.
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.