No argument that she's not yet palm up, but looking at the creases in the shirt at her rear shoulder leads me to believe her elbow is bent (creases due to some degree of scap retraction?).I agree it's hard to tell from one photo, but in that particular photo, she does appear to be locked out and pushing.
And I know it's due to camera angle, but the still image gives her forearms Popeye would be proud of!