Power Girl has had a fairly convoluted past (who hasn’t) but of course all that was wiped clean by the New 52 in DC. Now she and Huntress have formed their own counterpoint to Superman/Batman as World's Finest. And now before she adopted the name Power Girl, she was her world's Supergirl.
And they got rid of that costume she had. Okay...there is a lot of nostalgia connected to the costume but it really was..well...distracting. Maybe it was supposed to be. But she has worn the revealing costume from time to time even now in the New 52. By the way, the original Power Girl costume is a favorite of female cosplayers everywhere.
She has all the powers and abilities of Superman plus (and I think this is a BIG plus), since she is from Earth Two, Kryptonite has no effect on her. And this Power Girl is also a pretty darn good scientist and an excellent business woman (she runs Starrware Industries...or she ran it...who knows).