In trying to help out, I could not find them ( any of them!) on a census for 1940. I can tell you it looks like they were born and raised in Franklin County, so if you want a marriage certificate, you might send $1 and a SASE to
Franklin County Courthouse
275 Main Street
Rocky Mount, Va 24151
Give the names of Esther and William and Esther's parents and ask them to look for one around 1919 - 1920. You MAY be able to find that. I don't know why they are all so hard to find. I looked them all up in my Franklin County Cemetery book but none of them were named in it.
Sorry, wish I could have helped more. Franklin is one of my special counties I work in.