I had to repaint much of this today after looking at it for a long time and finally realizing where I had gone wrong. Sometimes it takes a lot of looking to really see where the problem lies!
I neutralized the background and lowered the shoulders a bit to give a more elegant appearance to the portrait.
Adding the necklace was fun! You can really go wrong with jewellery if you try to paint it with a lot of detail, just a few fine strokes and a couple of highlights and you are done. Examining some of Sargent's work in this regard is always illuminating.