I might as well make my hero char and play as them before I bring Ash in. 

Also she wouldn't be apart of the team, I doubt that Bat man would let a girl that went on a killing spree within a Catholic school for girls be apart of the team, also she is self destructive and Self loathing, so I doubt that she would be considered to be on the team, she would be first thrown into Arkham then considered that.