I think MJ will have long or short dark red hair.Which ever comes first.She'll be a B-Average student.She'll be very interested in Rock Music (just like Peter).MJ takes The Rocker look very literal.
My theory on her is that in the begining of the film she transfers to Peter's.From NEW JERSEY or, any other state -_-!!!The teacher introduces her to the class.Peter starts looking at all lovey-dovey like while the class whistle at her.Then Gwen intrupts Peter and gives him the look (from THE SPECTACULAR SPIDER-MAN cartoon).Peter and MJ start flirting which then causes Peter and Gwen to break up.Later Gwen dies at the hands of Elctro.Then afew days after that Peter and MJ finally start dating.
Sorry guys that turned into a SCRIPT/THEORY & IDEA type thing!!!!!!!!!!