Phyllis E.F. Porteous, one of Gwendolen Marjorie Howard's close friends, was the eldest daughter of Charles E.L Porteous (b. 1846) and Frances Eliza Drury (b. 1857) of Quebec City. Mr Porteous was the Manager of the Quebec City offices of the Bank of Montreal and the father of eleven children - Geoffrey D. (b. 1879); Phyllis E.F. (b. 1881); Conrad James (b. 1883); Batholomew Hazen (b. 1885); Helen M. and Arabella C. (b. 1888); Sarah Diana (1889-1900); Charles F.C. (b. 1891); Evelyn A.R. (b. 1893); Frances E.D. (b. 1895); and John (b. 1904). The Porteous parents and all of their children appear in the collection since Marjorie spent many vacations during the late nineteenth and early twentieth centuries visiting the Porteous family's summer estate, Les Grosardières, located near the village of Ste. Pétronille on the Île d'Orléans, Quebec. Phyllis and other members of her family also appear in photographs taken at or near Montreal and Métis-sur-Mer, Quebec, as well as in Kingston, Ontario, the home of Mrs Porteous's brother, Major-General Charles W. Drury, and his family.

Phyllis was one of the first of Marjorie's friends to marry. In either late 1905 or early 1906 she married Paul Sise, the son of Charles Sise, founder of the Bell Telephone Company of Canada.