Having done extensive research on this family, I would throw my 2-cents in on the subject:
Looking at this family from a logical standpoint, there is no printed and/or published form of documentation on this family, to my knowledge, proving who George Dowell married, who his parents were or who his children were with the exception of a bio written on Wm Lee, my g.g. grandfather.In the bio it is stated quite clearly that Priscilla America Dowell, wife of Wm Lee, was the daughter of George Dowell, a native of TN and Mary Vincent, a native of VA. (Priscilla's death certificate also names George Dowell with nativity of TN as her father, her mother is not named.)
However, most researchers of this line have based their research solely upon a "family birth record" in which George is listed as having married Polly Tomberlin.Dates of birth as well as a date of marriage were provided for both. This record goes on to name their children and gives dates of birth for each. Once again, there has been no printed/published account connecting any of those named to George, Polly, Mary or one another for that matter.
I have in my possession a record done by the grandson of John Dowell in which it is stated that John had a marriage prior to his marriage to Sarah Hickman. It shows that marriage produced a son named George.
If researchers of this line are willing to accept the "family birth records", even though it is not known who wrote it or when, then they should also be willing to accept the information provided by John's grandson.
While DNA would certainly prove a link to John Dowell, if in fact there was one, it would not prove who George Dowell married which seems to be the greatest point of contention with researching this family.
The only thing that seems to be clear on this family is that George Dowell was a native of TN.All census records on those named as his children name TN as his native state.Their mother is a different matter entirely.At least 4 of the children named Virginia at one point or another.Kentucky is also named as is South Carolina.
As for their children as named in the family birth records, printed documentation has been found on 7 of the 14 that are named. Again, no printed/published documentation has been found that actually names them as siblings or as the children of George Dowell and Polly Tomberlin or George Dowell and Mary Vincent with the exception of the bio above named.