Might be of some help???
Delia in those days was a pet name, original name usually Bridget.
There are three Bridget Farrell's registered in Galway in 1868. If you are really keen, you could order a photocopy version of all three.
1868 Vol.4 Page 625 Tuam (Galway,Ireland)
1868 Vol.9 Page 319 Galway (Galway,Ireland)
1868 Vol.19 Page 459 Ballinasloe (Galway,Ireland)http://pilot.familysearch.org/recordsearch/start.html#start
To order, application form can be downloaded from:www.groireland.ie