Prestalene is polyester viscose fabric - it's what pleated netball skirts and school skirts have been made from for years.

Skirts are not not made in 'children' and 'adult' sizes.  The sizes are based on the waistband measurement as shown below, and you may find that you'll need to take a bigger size than you would normally wear.

The skirt has elastic in the sides of the waistband which when stretched to the limit will give another couple of centimetres in waistband size - the measurements below are for an unstretched waistband.