The family were always told Bertie went off to Canada & I found a death for him 1950 Vict British Columbia but it appears he never returned to her or her child.
Is this his death notice?
https://www.newspapers.com/newspage/506775990/Times Colonist from Victoria, British Columbia, Canada Times Mon 6 Nov. 1950 pg 22
BERTIE CECIL MARSH Passed away on Tuesday, October 31, 1950, In Victoria. Bertie Cecil Marsh, of Lillooet, B.C., In his 72nd year. The late Mr. Marsh served with the Royal Engineers and the 31st B.C. Horse during the First World War. Funeral services will be held in the Thomson Funeral Home on Tuesday, November 7, 1950, at 10.30 a.m. Interment at the Colwood Cemetery.