This information came from my mother (now deceased) around 2000. It relates to my great grandfather's wife, Annie Jenkins, the daughter of a wealthy innkeeper – they owned a coaching inn called the Landor Inn. Not sure it is helpful but worth putting into the pot.
About 1846 a McCarthy eloped from somewhere south of Cork in Ireland to start a new life in Newcastle. It was a daughter from this family, Ellen McCarthy, who lived from 1860 – 1937 who was to be my mother's grandmother.
Ellen married John Johnson, a butcher from the South Shields area in the north east of England. They lived in South Shields and her daughter Eveline Johnson was borne there in 1888. Eveline was Eira’s mother; she died on 6th October 1968.
Eveline was to marry Esau Arthur Williams in 1911 and have three children;
1. Eira,
2. Yvonne, her younger sister by just 1˝ yrs, and
3. Illtyd Morley, the youngest of the family by another 2 years.
Arthur Williams was borne in Landor, outside Swansea. He was Managing Director of the Clayton Tinplate Works in Pontardulais as was his father, John Williams before him. John was not wealthy, but he was clever and he married Annie Jenkins, the daughter of a wealthy innkeeper – they owned a coaching inn called the Landor Inn. He used this money to buy shares in the tinplate works thus gaining the MD position, turning it into a family business with 300 employees, and later into a steel strip mill.
Arthur died in November 1950; He lived at Plas Gwyn in Pontardulais from his marriage to Eveline (my granny) in 1911 (when the house was built) until his death.
More available ... but not in relation to the Jenkins connection.