When I got home I went to trusty Google to see what else I could find out about her. There wasn't much more beyond the information that was on the card; just who her parents were and that she and James had children; one report had 7 daughters. James Ladson was an officer in the Continental Line during the Revolution.
The only other portrait I came across of Judith was this one (also from the Gibbes Museum Online Database ). She's obviously older but her eyes do not look like the younger one I saw in the museum at all. Nor do the fingers. It was also done by a different artist.
So I looked up the artist who did the first portrait - John Wollaston . Under the heading for his style it says, "... and his subjects are smiling and oval-eyed. His treatment of the subjects' eyes in particular is considered somewhat peculiar, and serves to identify even his unsigned portraits."
Ok, so I guess the mystery about the woman in the portrait was solved; she didn't have Down syndrome after all.
It is interesting though. Why Mr. Wollaston painted eyes the way he did. I wonder if there was some personal reason he painted his subjects with 'oval-eyes'.