Elaine, I tried to duplicate your search and could find a Rosa in the 1900 census with Eslie. I was unable to find them in 1910 but found Esli as a Widower in 1920. Death records were much better after 1909 when they became a state requirement, but they were still not good. I, also, was unable to find a death certificate for Rosa. There was a social stigma attached to mental illness and commitment, so people seldom used obituaries, even if they could have afforded them. Burial and tombstones were also expenses that could not be afforded. There were many burials in "Family Cemeteries" which are unrecorded.
Nancy Smith