On the forehand means that she's fall forward into the rider's hands and not using her hindquarters for impulsion or self carriage. Basically she's not balanced. I haven't ridden western competitively in a long, long time, so I don't know how they should be moving, but english horses should be moving from back to front; using their hindquarters to push up through a rounded back into a light, balanced forehand. At 3, she won't have all the muscles needed for that yet, but she should be worked in a direction to develop them. Just making sure she uses her hind end to work forward will start to help with that. With proper impulsion she'll begin to be able to balance herself and get her hindquarters underneath her.