http://cnnnancygrace.files.wordpres...k.us/img413/4910/balletposes1.jpg?w=378&h=354
FWIW, I showed this photo to a gymnastic instructor. She said the following:
The pose illustration shows the lower leg and toe pointing downward which is the classic dance pose. However, the "Helmet" girl's leg is a straight on shot and you can see the rounded beginning of the hip area, meaning there is no way a person could contort into this pose. Note the frontal position of the leg. Her conclusion was that there is another girl in the photo, on her side, facing the camera, doing a side leg lift.
Feel free to check this out. Not sure who it could be with her, but looking at the brushy location, it could be someone from other photos.