she's the product of parents who only had a kid so her mom could have the same accessory the rest of her friends did. comes from beverly hills money and was always a bit smarter than her peer group. so she has kind of a cool girl (i couldn't help it) vibe about her, that's vaguely disinterested/unimpressed by most things. however she was very excited to work with fincher, so she would've been better behaved on that set than most. also, elizabeth was giving a hell of a performance, so she would've had mad respect for her.