She's not really that skinny, but she looks better than a shorter girl would at the same BMI just because of her height & frame. As a short girl, I'm definitely jealous.
She's so pretty! You're right, she's an ideal size for a celebrity, IMO -- nice and lean, but not quite model-thin. I remember really liking her in Cloverfield.
House is one of my fave shows. I think she looks lovely and maintains her weight looking really healthy and not tired or weary in the face. Very pretty too.