Her hair's a more flattering length, and still such a lovely colour, but boy does she look tired!
I think Sarah does look older than she is--her face looks pale and haggard. I think smoking is probably a lot to blame for that; the Daily Mail recently had an article with pictures of Kate Moss (a smoker) without makeup, and although she's only in her 30s, she looked much older.
Sarah's hair is pretty, though.