Mabelle Gertrude Morris enrolled in Army Nurse Corps, at Minot, on Aug. 4, 1918; served in Base Hospital, Camp Lewis, Wash., to April 13, 1919; General Hospital No. 21, to discharge. Relieved from active duty at Denver, Colo., on Sept. 25, 1920, as an Army Nurse. In the 1920 census, Mabel is a nurse in the U.S. Army Hospital in Colfax, Adams, Colorado. I can't find her in the 1930 and 1940 federal censuses, so a lot could have happened in the decades between being a WWI army nurse and when she got married in 1961 in California.