In the puppy preschool classes I used to teach, we taught sit, come, down, stay and had socialization exercises such as a bouncing basketball (you wouldn't believe how many dogs that scared) and the tunnel. Most of the stuff we did was from Temperament testing exercises. We usually taught the down from the sit much like Scottie said, but took the treat down between the forelegs and slowly drew it out away while holding the hindquarters in place gently. I never had a puppy fail any class because I figured if the dog learned one thing at all, that was an improvement and so they graduated (as long as they CAME to class).
I got several students from a Professional Training school because of the same behavior from the instructor. I don't know how the man kept a school open, but he always had about 40+ dogs in class and he would point out the ones who hadn't "done their homework" as bad examples. Have you all learned the "watch me" command? It's a method of teaching the dog to look you in the face and pay attention. That was always our first command to learn. Use her food dish to start teaching it and once she's comfortable paying attention to your face (she may be shy since eye contact can be a dominance thing -- keep a soft look on your face and reward for even a quick glance), you can use the watch me command to keep her focused. Are there a lot of puppies in the class? Maybe she's real interested in playing with them. The PWD is a very active breed just like all the field breeds and are very intelligent, ergo, easily bored and nosy. I used to recommend using semi-moist cat treats for training treats since they're flavor intensive and easy to break into smaller pieces and easy to carry in your pocket in their pouch. They don't add a enough to the diet to screw up the nutrition, but most dogs will do just about anything for them. Also, time your practice sessions at mealtimes and you'll have her attention if you have the food bowl in hand. Good luck and if that instructor doesn't nice up -- go elsewhere! You don't have to accept that kind of treatment, but you might remind her(?) that bad word-of- mouth usually goes farther than good word-of-mouth advertising.