I assume you're thinking of the curvaceous way she's usually drawn. I'd really rather not see her portrayed that way. I've got nothing against curvaceous women in principle, but it's a terrible body type for a catburglar, someone who's supposed to be light and agile and able to slink through tight spaces. It's a mistake to render Black Cat and Catwoman that way, a triumph of cookie-cutter fetishism over good character design.
Character design is not necessarily better when it's realistic. The characters you're talking about are defined by their sensual nature just as much as their profession. If you ignore those qualities, you miss the point of the character and end up with something else instead, something that is not nearly as interesting or enduring.