Thank you for taking the time to respond!
To answer your questions:
During the twitching period there is a change in her breathing: it comes in gasps and becomes more rapid. Our biggest worry is that the episodes are getting longer and the twitching sometimes turns into a cramp for a brief period on her hands. The hands turn inward with the fingers bent. According to the neurologist who briefly looked at the EEG there are no signs of epileptic activity but I have asked for a copy of the EEG and will get a second opinion. (It's a little disheartening that as an engineer at I need to pay more in depth attention to complex machines than a human being gets when hurt - sorry, just venting)
With respect to the neck, she is receiving physical therapy with exercises aimed at getting her neck better. Is it OK to still have pain at the site of the injury a month after the event? The constant pain is gone, but the area is very sensitive to touch. (It's the backmost area of the occipital bone)
The posture is with her palm facing down with the arm raised almost parallel with the ground, with the axis of the upper arm, the forearm and wrist (pointing slightly downward) rotated by about 30 degrees from the fully stretched position. Something like this, with the wrist being the leftmost symbol: /\/
This is important for her because as a musician this is the position of holding her bow.
With respect to what caused the fall, we were not there so I only have a second hand account as our daughter does not remember the exact way she fell. The girl she was running with describes is as her slipping in a puddle. She did lose consciousness for a brief period (a few seconds) after the fall.
Thank you again for your responses!