Finally sorted out most of the puzzle here!
Starting here-
Kitty Ryan was born circa 1880 in Portlaw, Co. Waterford. I'm unsure what the name Kitty was short for. Her parents were Michael Ryan and Kathleen Ryan (nee Fogarty). She had a brother, Thomas, but I don't know if he was older or younger than Kitty. Different records list Thomas' birth as 1887 - 1881. At the time of Griffiths, the family lived at 33 Queen Street, Portlaw, also known as The Bridge, Portlaw. The Michael Ryan mentioned in Griffiths would have been Kitty's grandfather. It is believed the family continued to live there for many years. I can find no trace of the family in either the 1901 or 1911 census, nor any record of Kitty's birth or baptism. I know her brother Thomas moved to Croydon as he appears in the English 1901 census.Kitty wasn't Kitty (or Catherine) and she wasn't born c1880. Mother was Catherine/Kate Higgins (not Fogerty). Ryans lived in Portlaw but at various addresses there. The Michael Ryan in Griffith's Valuation was not the grandfather of 'Kitty.'
Starting with Thomas as he's the child that can be traced in English records. The 1939 Register apparently gives his date of birth as 6 July 1879 and the 1911 census gives birthplace as Portlaw, Co. Waterford.
This is my source for 1939 Register and original needs to be verified but the date does fit.
https://www.familysearch.org/en/tree/person/details/LC59-RNQI've lost count of how many times I searched for Thomas' birth registration but armed with an exact date I searched again. Only one Thomas Ryan registered 1879 in Carrick on Suir district (which includes Portlaw) but parents are James & Bridget and it's not Portlaw.
Then I searched the register pages which covered the July/September quarter of 1879 in Portlaw sub-district. Bingo! Found a son born to Michael Ryan and Catherine Higgins on that date at 6 Bridge Street but father's residence was Curtis St. (more on addresses later). The name given for the child was Michael not Thomas but a stamp on the right side of the page indicates a new (amended) certificate was issued (too difficult to read date)-
https://www.irishgenealogy.ie/files/civil/birth_returns/births_1879/02904/2064011.pdfto be continued...