Then we have the youngest individual to don the persona: Mattie Franklin, as portrayed by...
Alexis Bledel (I think it was
Sin City but something about Bledel has always made me favour her during fan-casts, especially for younger characters. She's not quite the ditsy punk -- a contradiction I know -- as Mattie is but being a talented actress you'd think it might be a challenging part for her, it'd certainly be interesting to see her in a role like that)
Chloe Dykstra (a relatively unknown at this point, she's starting to pop up in a lot of places, is of the right age and get this -- appeared in
Spider-Man 2 as one of the passengers on the Train. If Raimi-verse is canon, you'd think she picked up the mantle during Peter's absence in that movie in some bizarre expanded version of the film)
Lyndsy Fonseco (the girl from
Kick-Ass. She appeared in
Boston Public and has some experience playing a character in a sprawling urban crime-drama, perfect for Mattie and of the right age as well)
Tania Raymonde (the girl from
Malcolm in the Middle)