This is GREAT!
But...I don't think the powers necessarily need to be tied to the people. Mainly because if my daughter wants to be the girl but wants to be Sciency or Sporty, it could be her choice.
Maybe I'll make these into little cards that you can select by choice or by random draw at the beginning of the game. I'll post the printout if I do.
You could use a little draw bag too for a random draw.