The one consistent element, imo, is the cat-and-mouse game between her and Batman. Even in the original Golden Age stories she's trying to seduce and Bruce would let her get away just so he can prolong the chase. He seemed to enjoy trying to catch her, lol.

I would say, after Post Crisis, her origin is cemented as a street urchin turned thief who may or may not have been a prostitute at some point as well. The Pre Crisis origins are fun to look at in terms of where the characters was and where she ended up today.