Sorry I took forever to get back to you on this, I literally just got back from work.
SPOILER ALERT TO ANYONE WHO HASN’T READ THE ISSUE YET: STOP HERE!
That out of the way, basically she destroyed all of Michael Holt’s labs through a series of “freak accidents”—I’m assuming—in response to Michael sending in the troops to destroy her lab on Starr Island. Which is very un-Power Girl-like.
Mind you, it was already a mistake before to write her off as someone who used Michael and stole from him (though in all fairness, this was not entirely on Levitz), but this just takes the whole cake. Kara would never do something like that.
And then Helena was very condescending towards her afterward, which again, is not very Helena Wayne-like.