Try dyeing a large pillowcase orange, sew green leaves and a drawstring around the open end. Make leg holes and armholes in the bottom and side seams, maybe sew the corners at the bottom a bit rounder. Put GD in it, gather around loosely at the top and stuff scraps of batting around her to fill it out! Just be careful to keep neck opening loose to be safe. orange tights and shirt under it will keep her warm ( hmmm what IS the temp in Australia on halloween?).