With expectations of finding more details on Mary, I requested her daughter's (Una/Viola) birth certificate from Illinois. No birth certificate was found. I reviewed Una/Viola's funeral book again slowly, but there is not any mention of a mother, Mary or any father.
Lucky for me, Una/Viola died in Missouri and our Secretary of State's Office has death certificates from 1910-1960 available online for free. Una/Viola died in 1960, so I was actually very lucky! After downloading the certificate I started extracting the information it contained. The parents are listed as Joseph Evingham and Martha Smith. This was the first reference I had found of her father's name, that information by itself was exciting. However, Martha Smith? Smith? Really? Is Mary a common nickname for Martha? I didn't think so and this now creates more questions. Is the Mary listed in the census records with Una/Viola really Martha and is it a coincidence that the man listed as a servant has the last name of Smith?
I am now off to see what I can find about Joseph Evingham and Martha Smith in Ohio and Illinois. I will also continue to research Una/Viola in an attempt to find more references to her parents. The quest continues!!