I see that you have a copy of the material Jack and David provided at the reunion.
There is only one other thing I have to add to this, which I've mentioned to Jack, MANY TIMES, and that is, one has to indicate that"a surname is IMPLIED" by using a question mark [in brackets] after the surname so that those reading your postings will know you lack proper documentation to prove what you strongly suspect is correct.
It is quite likely you are correct in your assumption that your Mary is a Vardeman but it would be dreadful should at a later date you were proven to be incorrect.
I, too, face much the same problem with my Brown line. The ancestor is named James R. Brown.His mother [Elizabeth], and siblings live with a Nancy Rich for several census'. His siblings are named after Nancy Rich's son and one of her sisters. I feel strongly that Nancy Rich is James R. Brown's grandmother, but I have no documentation therefore I have to use the dreaded [?] when listing his mother, Elizabeth.
I'm sorry, I don't mean to be lecturing you but I do feel strongly that it is best to be cautious when posting information for which we lack documentation.