Buried in the news that Joseph Gordon-Levitt is officially on board as mob scion Alberto Falcone is the fact that Nolan is casting about for a "street-smart Gotham girl." Now, who could that be?
According to Variety, director Christopher Nolan has his eye on Juno Temple (Year One) to play the role of that Gotham girl. Of course, there are plenty of ways to employ an adolescent in Nolan's Bat-verse. Actually, no, there aren't. Given that description, Temple can't be playing Talia al Ghul, and, unless The Dark Knight Rises skips ahead at least 10 years in time, Barbara Gordon wouldn't be old enough to be Batgirl.
So, will Temple be playing a random kid on the street or Batman's Number One?
And it's not as if there's no precedent for a female Robin (see: Frank Miller's The Dark Knight Returns). Besides, Leach and Hood notwithstanding, Robin is a girl's name.