Griffith Valuation book place in Kilkenny in 1850 possibly about right for the great great grandfather.
The name William Doyle appears 158 times. There are 8 William Doyle's in the Parish of Aglish, Townland of Portnahully.
Also there is a William in the Parish of Portnascull, Townland of Luffany, Poor Law Union Waterford,
(would live within 12 mi. of the town of Waterford), tenant of Hugh Power, Esq.
1f house, outbuilding and share of land with 15 tenants 403 acres 2 roods 21 percheswww.familysearch.org
( you should go through these)
Catherine Connolly birth registration July-Sept 1893 Latter Day Saints microfilm
Vol.3 Pg. 367 #101064/004193978 (no parents name listed in the record but must be on the microfilm)
Alice Doyle birth registration 26 September, 1875 mother Catherine (no last name) but these records
so come with mother's maiden name but the LDS seem to have left that part off the record. Perhaps the film would show
Have you looked in the census for 1901/1911, www.census.nationalarchives.ie
The current telephone book for Kilkenny has 2 Doyles of 158 at Slieverue, then others close to that location. If you click on the 'refine your search' you will find these two Doyles as well as other Doyles
with addresses sufficient for mail delivery, no postal codes required.
Personal information, stories and the like usually comes from family members. Today's means of communication would be Facebook which is apparently great for finding those lost cousins.
RC Parish Maps:
Slieverue is in the s.e. corner of Kilkenny and borders Wexford and Waterford, which explains the Waterford Poor Law Union. A PLU often went across county lines and took in parish's, villages within 12 mi. of the named city.
Try the Kilkenny Library for their Local Studies Department which from what I read is located outside the library. www.kilkennylibrary.kilkenny.ie