There is also the fact that the children resembled TJ including the reddish hair.
I have no ox to be gored here but the evidence I have seen strongly indicates that the children were Jefferson’s and this has been around for centuries, it didn’t just pop up.
Many of “TJ’s” male relatives had red hair. Which buttresses, particularly, the male hair color pattern as a sex linked genomic trait. Speaking as a geneticist and forensic pathologist: Hair clips do not contain DNA at all. They are made of protein from dead cells that have lost their nuclei. They will never be used in DNA tests. Also, the number of generations that have passed since “TJ” died. DNA is inherited half from the mother and half from the father In any one generation one would expect to find half of the DNA in common between a father and son. When there is more than one generation separation, then the DNA in common is a smaller percentage. That is it gets harder to make any clear conclusion the farther the distances between generations— for ANY definitive conclusion.
Besides all this is the notion that Jefferson would ever have (unlike his quite well known randy slave abusing male extended kin— who clearly DID) slept with his wife’s half sister, aside from the fact that she was a slave. The later manumission was a fact of the enigmatic Thomas Jefferson’s true thoughts of the institution of slavery, and the restrictions of VA state law at the time.
Much as we are reduced contemporaneously with low rent media based “sex abuse” trial by “citoyenne Tribunals of public media” no proof needed (ironic, as Jefferson witnessed the Reign of Terror in France murdering innocents on a changing basis weekly, and politically), this highly energetic activity to self-righteously condemn a Founding Father genius is driven by a political agenda, and except for the uninformed, has failed.