We know this now, but was the son who was sold ever told who his father was? Unless it was documented, there is no way of knowing.
"The essence of the Woodson family history as recounted by Minnie Shumate Woodson is that:
Young Tom told the fact that he was the son of President Thomas Jefferson and Jefferson's dead wife's half-sister. Young Tom had a misunderstanding with his father so he was sent with other slaves to live away from Monticello to John Woodson's farm. When he came of age, he received money from Jefferson or Woodson to buy a farm. Young Tom, who was never a slave, bought the freedom of his wife and children. He took the name Thomas Woodson and went to Ohio to live. He bought a farm and coal was discovered on it. He sold the farm that had coal on it and invested the money in businesses in Pittsburgh."
https://www.ohio.edu/orgs/glass/vol/1/11.htm
"The second, and more infamous, Callender article states Tom's "features are said to bear a striking although sable resemblance to those of the president himself." Although the term "sable resemblance" is ambiguous, any child of a Jefferson-Hemings interlude would have been only one-eighth African and had very light skin. Correspondingly, at least two of Sally's children, Beverly and Harriet, married into white families and transitioned into the white world unnoticed. In short, Sally's children could not be depicted as "sable". So, if the "Tom" described by Callender was Thomas Woodson and he was "sable", then, in all probability, he either wasn't Jefferson's son or wasn't Sally's, since by all outward appearances their children would be perceived as white or `high yellow'."