You may have this information already. From History of the Ely O'Carroll Territory by Rev. John Gleeson reprint Boethius Press Kilkenny Ireland 1982 first published 1915
Chap 11 Genealogy of the O'Carrolls. Page 17 Only giving bare outline as too long. " The present representative of this family is William Henry O'Carroll of Oak Park House, Arrabeg Co Tipperary near Birr. Captain John Carroll of Arrabeg was brother of Roger Carroll of Kilfada Castle in Eglish, parish of Borrisokane Co. Tipperary and both families trace their descent from the line of Emmell castle. the genealogy of the O'carroll family of Arrabeg Kilfada and Emmell is proved by the official, certified copies of the various wills and deeds which are now deposited with William Henry O'Carroll of Arrabeg , Birr ...." "the lineal living representatives of the great house of Emmell are two poor men, father and son, who support themselves by labour. Irish prodigality brought about the loss of Emmell Castle and estate. The senior representative, now living held a farm of sixty-five acres of land which he lost. Even still, though poor, he is styled by the people as 'Mr Carroll' "
And a note "A second son of this old man lives in Emad Louisiana USA, he has two sons and a daughter."
Hope this is of use.
annclare