I just had this crazy idea.
So I think DC should kill of new52 Power Girl. However next issue PeeGee returns but she is a little older, more muscular and much more mature. It would be revealed that this Power Girl somehow survived the universe altering events of Flashpoint and is a refugee of the pre52 universe.
Pre52 Power Girl was unique in that she was a survivor of pre-crisis Earth 2 and spent decades serching for her true identlty. In hindsight this added to her character in that she was a lost person who had to adapt and love this Earth when she could never go back home. New52, she is still able to go back home and there isn't that sense of loss as she had before.
PS. And bring back Atlee.