Power Girl has been one of DC's more popular characters over the past few decades. Despite being a version of Supergirl from another Earth, Power Girl became known as a hero in her own right, adventuring separately from the legacies of Supergirl and Superman. However, since the New 52 rebooted DC continuity back in 2011, Power Girl's role in DC's history has become somewhat more diminished and much more complicated.
While the pre-Flashpoint Power Girl worked closely with the Justice Society of America as well as the Justice League, the absence of one and the closed ranks of the other meant there was no place for Karen Starr on DC's rebooted Earth. Instead, the character returned to her roots of Earth-2 for a complete retelling of her history.
Originally, Power Girl was a resident of Earth-2 when she debuted in 1976's All Star Comics #58, by Gerry Conway, Ric Estrada and Wally Wood. As the New 52 began in 2011, Power Girl got her own series alongside Helena Wayne's Huntress in World's Finest by Paul Levitz, George Pérez and Kevin Maguire. This series saw the two heroes of Earth-2 (who were Supergirl and Robin there) stuck on Prime Earth where they adopted the new personas of Power Girl and Huntress.
The series ended with the duo returning to their original home of Earth-2 to find it very different from how they left it, primarily with their family, Batman and Superman, gone and new versions taking their place. Power Girl's story continued on Earth-2 in the series Earth-2: World's End written by Marguerite Bennett, Mike Johnson and Daniel H. Wilson with art from Eddy Barrows, Jorge Jiménez, Paulo Siqueira and Ardian Syaf. This saw Power Girl's home of Earth-2 destroyed and its inhabitants looking for a new home. With the story continued in the Convergence event, the Earth-2 inhabitants found a new planet nearly identical to their Earth. In Earth 2: Society by Wilson and Jiménez, Power Girl (now wearing her family crest again) and the heroes of Earth-2 manage to rebuild the world they lost and achieve their happily ever after.
This is not however the end of Power Girl's New 52 adventures. In fact, this is where the character's current place in continuity gets all the more complicated. Power Girl, during the time of her trials on Earth-2, appeared in the series Harley Quinn and Power Girl by Amanda Conner, Jimmy Palmiotti, Justin Gray and Stéphane Roux and made subsequent appearances as part of Harley Quinn's Rebirth series by the same team. However, there is the small matter of Harley Quinn taking place in its own world but affected by overall continuity, which explains how she can be part of it and Earth-2 simultaneously.
However, Power Girl's complicated history in current continuity doesn't stop there. The character appeared in Deathstroke Annual #1 by Priest, Hama and Cowan which saw her trapped in a space between worlds with no way out where she remained at the story's conclusion. However, in her next appearance in Green Lanterns #40 by Seeley and Bagenda she is somehow back on Prime Earth talking to Blue Beetle, and in Dial H for Hero #10 by Humphries and Quinones, she is on Earth-2 assisting her fellow Society members in a multiverse montage.
The last time couple of times Power Girl was spotted were alongside the JSA in Doomsday Clock #12 by Johns and Frank and catching up with Harley in Harley Quinn and the Birds of Prey #1 continuing from the Rebirth series. However, Doomsday Clock's interpretation of the JSA was made to be outside continuity in a way not unlike the Harley Quinn series.
Finding out where Power Girl fits into the DC Universe right now, whether it be on the current Earth, Earth-2 or somewhere in between remains a mystery. Hopefully, Power Girl's next appearance will clear up where she stands in continuity and continue her story in a way that respects her pre and post-Flashpoint history.