Hi Tim,
I am not sure why this painting has such a modern feeling for me, but it does. I wonder if anyone out there knows when it was executed. It almost has a Bougereau or Vigee "feel" to it but I still think that it might be more modern. Perhaps it is the scan, or perhaps the contrast has been exaggerated by manipulation, but most 1800's art that I have observed has a softer feel to it, and the models usually have softer, rounder, faces...with the exception of some. Perhaps it is the long arm bones that signal a tall girl to me which was real unusual back then. Now, mind you, I am probably going to be very wrong about this so please be gentle when you say, "I told you".
I have no idea why I am getting this feeling of modernity from it, but I would put it more in the 20th century. But, then again, I am 85 percent wrong on guesses most of the time, so I am probably wrong on this also. But it sure is fun making guesses.