Oshyan, the hair problem was my first thought when I bought the model, too.
Meanwhile I decided not to show the girls face in the animation.
The face and her expression do not fit the scene at all.
Instead we'll have a 300frames animation of her back and Riddick turning his head into the morning sun.
I had to use quite low GI settings to avoid problems with the ponytail. I hope it won't look too bad in the animation.