I am afraid I don't recognize the name Johanna from any of my McSwiney records.
Like you we are still searching the Irish records - probably need to make a visit to Whitechurch cemetary.We don't have much solid information to go by - only letters from Fr. Denis McSwiney Right Rev, PP, VG(1823 - c.1906), son of Roger, establishing some names and dates of his family.
The patriarch was Daniel McSwiney(1730 - 1786) Place of Burial:Catholic churchyard of Whitechurch, five miles north of Cork and one mile south of Dromboy - formerly spelled Droumboy, where he had a large farm.Father of Patrick, Roger (Priest), and Morgan.
Perhaps Patrick's son Denis is your Denis McSwiney?If you find any further records please let me know.Thank you!
The spelling of the name McSweeny was McSwiney in our branch of the family in Ireland and in those who emigrated to England.The U.S. branch changed the spelling to McSweeny.