All of her living descendants who possess the haplotype in question are white as white can be. When Sally's son Eston was born, he was 7/8 white. That's why I get so burned by ignorant statements like the one above, claiming that these folks are being "excluded" because of the "color of their skin." Give me a break!
Who cares? My comment was tongue-in-cheek. The question of who is related to who may be amenable to genetic analysis. However, this isn't your average country club--if one branch of the family doesn't want to identify with the other, or doesn't even think they are related, whose business is it? Not the government's, certainly. Ours, only in the sense we might care about celebrity gossip.
Actually, Sally Hemings was at least half-white herself. It is widely thought that she was the half-sister of Jefferson's wife.