Mhm, i think slapping is a problem and not sth the dog will not learn from. I kinda get with being frustrated with dog and having to be rough, like the bit with her putting the dog on its back that's sth i have seen trainers do as well, but hitting is not okay in any circumstances. I wouldn't go as far as to say she shouldn't have dogs, but hopefully she learns from this all.. and also goes to get help with getting her dog trained it seems like she has no control over the dog. That's quite hard breed to get though if you don't know how to train it, I wouldn't get doberman myself.