First, prevent your son from teasing the dog by not putting the two in that situation. Second, asap, hire a trainer for private training. If you are up to the required management and training, go for it. If you are not, the pup will be better off in a new home, especially now she is till so young. You have to think about the fact that this can easily spin out of control, if it isn't already. Your pup will quickly grow stronger and it will result in more serious aggression. I vote for sanity and harmony in the family and for protecting the soundness of the dog.