Millicent “Millie” Lyall Buck was born on November 22, 1899 in Brantford, Ontario to George Philip Buck (September 5, 1864-September 21, 1925) and Mary Evelyn "Effie" Agnew (June 23, 1868-September 17, 1941).
George Buck and Mary Agnew were married on June 19, 1890.
Millicent was raised alongside her sisters Phyllis “Fiddy” Agnew Buck (1897-1959), Kathleen Isabelle Cockshutt (April 26, 1895-1961), Evelyn Alice Foster Ferguson (1893-1979), Florence "Flore" or "Tiny" Mary Louise Middleton (August 2, 1902-April 22, 1983), and Isabelle “Diddy” Alexandra Burt (1901-1980).
Millicent attended St. Hilda’s College in Toronto, Ontario between 1918 and 1920.
On January 19, 1922 Millicent married George Alexander Forbes. Millicent and George had twin daughters named Millicent Elizabeth “Betty” Forbes and Margaret “Peg” Isabel Forbes. The twins were born on July 10, 1924.
Millicent died on September 7, 1973 and was buried in New Hope Cemetery in Cambridge, Ontario.