Here's the marriage details for Rosanna Archbold (same for John Balfe, so a match - Naas is in Co. Kildare) in case they turn out to be Ellen Balfe's parents:
Ireland, Civil Registration Marriages Index, 1845-1958
Name: Rosanna Archbold
Date of Registration: 1874
Registration district: Naas
Volume: 12
Page: 749
FHL Film Number: 101252
Happy hunting!