Wolfgang:

"Carrigrua" is given in Paddy Berry's book "More Songs of Wexford", with the following note:

"Written and sung by John Furlong, Ferns, All-Ireland ballad singing winner in 1985 at the Fleadh Ceoil in Listowel"

Just a few minor corrections based on that text:

Verse 2.3: Ferns' old town
2.4: Where the old church and abbey in ruins fall down

4.1 : I can see Boolavogue and the bold Shelmalier
4.2 Where Father John Murphy with his life he paid dear
4.3 … his forces did band

5.4 … in heaven be crowned

There is also a sixth verse, which slots between 3 and 4 of Brenda's version:

From sweet Carrigrua I see Vinegar Hill
And places where our heroes their blood once did spill
While trying to free Ireland from the grasp of the foes
They were sadly outnumbered and lost to the yeos.

Finally, Brenda seems to have switched the second half of her verse three with that of verse four.

Regards
p.s."The Harrow" is a placename