For all forms of dancing hair should be securely fastened off the face.

How to Make a Proper Ballet Bun: Brush your child's hair into a neat, medium high ponytail. Put hair into an elastic ponytail holder. Coil the ponytail in a clockwise direction. Using large sturdy hair pins, begin attaching the ponytail to the head around the elastic ponytail holder in a clockwise direction. Continue until you have a circular bun on the head. The shape should be flat, not pointing out of the head in a cone shape. Apply a hair net, to the bun and continue to double the net around the bun until it doesn't stretch anymore. Add a couple more hair pins to keep the hair net in place. A light application of hair spray may then be used to keep hair smooth around the face.
If you need assistance, please make an appointment with your child's teacher and she will gladly help you.