Its a nice enough dress, but I am not sure about the neckline. IMO, it draws attention to her shoulders and since she has wider shoulders (Note: that is not an insult, its one's bone structure and I have a similar shape as well), I don't think she would want attention drawn to them, I know I wouldn't for myself. I think her assets are her waist, and her long legs.
"It is a truth universally acknowledged, that a single man in possession of a good fortune must be in want of a wife."--P&P