Whatever this kindergarten is, get her out of there. You don't need gangs of dogs bullying your puppy.
Beat me to it!
She is supposed to be getting socialized "not" traumatized! Your job is to protect your dog. If this "training" class can't keep puppies from ganging up on your pup, there inept anyway.
Your dog gets traumatized here and you are going to have serious issues to deal with down the road!