User blog comment:Hulk10/Powergirl/@comment-25737724-20141209144949/@comment-1038387-20141209150451

You know, I don't know. I said that way back in March. Off the top of my head, the only thing they've ever been compared in is their... balcony, and Black Canary claimed Wonder Woman was second in that.

The DC Encyclopedia simply lists Diana "one of the strongest beings on the planet". It calls Power Girl's power "incredible superstrength", but this was during the time when her origin was still in question, and all ties with her Kryptonian heritage were ignored.