Yeah... something I just got to thinking about... Power Girl has a rather... complex history - but what exactly, is that history at the moment?
I see her appearing on Harley Quinn -covers at the moment, so I'm guessing she's back on Earth-0? But what with the recent change of the Superman-mythos, the morphing continuity that is Rebirth (not finished yet, I know), her time as a new clear origin in the New-52 (entirely separate from post-crisis and the original Earth-2) and generally the bringing back of Post-Crisis elements...
I find myself wondering, once more... WHO is Power Girl??
Has this been cleared out, or is this one of those things that are still in flux, and might become clear (yeah right...) in the future?