panel from Supergirl vol 5 #12 showing Kara in a tight fitting blue crop top t-shirt and blue skirt in red boots dancing in a boobs and butt pose with the camera angle looking up
Panel from Supergirl vol. 5 #9 showing Kara (Supergirl) in a black Superman t-shirt and red dress talking to Captain Boomerang in a bar, he says "I know a great place. No carding, so you won't have a problem." She says "I'm a girl in a tight t-shirt, I can go anywhere I want." he says "Ha, you're a real piece of work, lemme settle up."
2 panels from Supergirl vol. 5 #11 showing Supergirl (drawn like a Bratz doll with giant eyes and huge pouty lips) in her undies rubbing up against Captain Boomerang, he says "Jeez then what does that make me?" She says "A big brother with icky feelings about lil sis he doesn't know what to do with?" He looks upset and says "You are so so evil" as she leans against him and says "You love it"

The Instinctive Superheroine Boobs and Butt Dance

Oh Supergirl and that run (Supergirl vol. 5 #0-#19).  This Supergirl boobs and butt pose is probably the least of her problems (and at least the art is decent as opposed to the other issues), although the context of her dancing in a club is during a story arc where they constantly remind us that she's a) underage 2) loves teasing men about being underage and iii) apparently uses it to sneak into bars?

It was a strange period to be a Supergirl fan. >_<

Anyway, yes, Supergirl's like everybody do the Boobs and Butt!  Of course this being the superhero universe, every single superheroine instinctively knows that dance from birth.

(Panel from Supergirl vol. 5 #12, DC Comics, submitted by anonymous; additional panels from Supergirl vol. 5 #9 and #11 added by me)