Harley Quinn also works fine for me, although I don't know how that jester costume would square with the dark and gritty Nolan-verse.
Think Goth chick like Faruza Balk and Harley fits perfectly in Nolan's universe.
I'm think more along the lines of Poison Ivy or Talia.
I can't think of a crime Catwoman could commit in Nolan's universe that would require Batman over Gotham PD. Catwoman is just a thief. Unless she's the love interest to Wayne but unknown secret partner to Batman in the film. The villain would have to do something that threatens the city and can redeem Batman in the eyes of the public after what happened at the end of "Dark Knight".