I've just started playing this game! Actually, I rented it when it came out, played a little after Booker gets Elizabeth out of the tower, and then had to take it back. I recently bought it for twenty bucks. So I'd assume you like this version of her, rather than the less risque version when she's in the tower. I'd have to say I prefer this one. It's almost a hybrid look between the old Victorian, straight-laced ideal and the 20s flapper openness. But was this a real look in 1912? I don't know much about the period.
And, btw, do you think Bioshock Infinite is steampunk?