Muriel Lucas was the granddaughter of Captain Allan Finlayson through his oldest daughter Katie Maude. Allan Finlayson was born in Belfast, Prince Edward Island, the son of Angus and Catherine (McDonald) Finlayson. On 14 November 1872 he married Annie C. Forbes with whom he had at least nine children. A master mariner, Captain Finlayson was captain of three of the early mail steamers, the Northern Light, the Stanley and the Minto until he left the marine service in 1920. He died on 31 July 1928, predeceased by his wife who died on 19 January 1916. Another of his daughters, Alma Jessie Finlayson, born on 7 April 1883, trained to be a teacher at Prince of Wales College in Charlottetown and at Columbia Teachers College in New York.