It's not neccesarily a west Cork song but the poem/song Mise Éire, written by Patrick Pearse mentions the Hag of Beara (Chailleach Bhéarra).

A performance of the song by Sibéal Ní Chasaide was featured as part of the 1916 Easter Rising centenary celebrations.
https://www.youtube.com/watch?v=dGhblvkfitk