Make sure that when she pike's on the bar she is only putting her toes on, not the centre of her feet. That way when she gets back around the bar it will be at the centre of her feet and the weight will be distributed correctly.
Make sure she isn't banding her knee's too early, she should be just about around before she bends her knee's to stand up.
It can be a psychological thing, get her to imagine she is doing two sole cirles in a row so that she will keep going.
Make sure she is keeping her feet on the bar and not jumping off, get her to try to stay on and forget about jumping off for now, if they think about jumping off it often happens too soon.
If you have a straps bar practise in there.