The records show that William Keoghoe, son of William, married Maria Brouard daur of John Zacharia Brouard on 30th July 1835 at the town church, St Peter's Port. I have seen a copy of the register entry.
Maria was the daughter of John-Zacharie Brouard and his wife Marguerite Mouilpied, born 28th August 1815, and baptised the 13th September following, at the town church, St Peter's Port.
Maria's brother John Brouard also came to London at some point; Maria Keoghoe was a witness at his marriage to Sabina Claridge on 27th Feb 1837 at Camberwell St George. John was a brazier and tin worker in the 1851 census, and a tinman in 1861.
We were unable to positively identify William Keoghoe senior with any soldier of that name. either the William Keoghoe assistant surgeon, on the Waterloo Medal Roll, or the William Keogh born c1788 Toughmaconnel Roscommon, who served in the 72nd Foot.