Now I have two Alexander siblings. I received a response to a query on an Ancestry message board a few years back from a fellow researcher, John. Based on information he had received he indicated that Elisabeth and George's parents were John Alexander and Polly Ferguson. His deductions are sound, but I have yet to find documentation that proves this link. I did find a John Alexander living in Johnson County, Missouri in 1850. He is widowed and with him live five children, all born in Missouri, to include a George. This George is a year or two older than "my" George.
I added the above individuals to my practice tree to see what information I can find on them that may connect them to Elisabeth. And it's a good thing, too, because Araminta Alexander came up with 6 Ancestry hints. Each one was a census with the married name of Hull. I decided to look for her marriage record and found the following record from Johnson County, Missouri.