Introduction of new 12 wk puppy at home to 13 month old

Question
We have had our 13 month old female German Shepherd, Sasha, since she was 12 weeks old and have just brought a new puppy into the household, 12 week old male Lab named Max.

It is day 2. The initial meeting went pretty well. We did it with both on leashes with a gate in between. They sniffed and didn't show any aggression. Neither growled or has growled.

I'm a little concerns over how Sasha is treating the new puppy. She is mouthing the puppy a lot. Sasha mouths him around the neck and the feet/legs. She is doing it a lot and worrying that she is tormenting the puppy. Sasha often runs after the puppy and tries to mouth him and push him around. Within the first hour of meeting Sasha was doing this. The puppy used the normal submissive reactions to tell Sasha I give up (rolling over on back and licking Sasha's snout if Sasha continued to hang around after rolling over). Sasha sometimes ignores the rolling over on the back and still pesters the puppy. The puppy tries to use his legs to keep Sasha away. Sometimes the puppy will give a soft yelp. The puppy yelps are surprisingly soft. I would have expected more volume. The puppy certainly can make a loud voice at crying and howling (first night shut in the bathroom).

I've noticed a little more fight back in the puppy with this continued behavior. I'm concerned that the puppy is being bullied by Sasha and whether it may lead to defensive aggression in the puppy.

Some background on Sasha. Sasha was not socialised with other dogs at all for the first 2 months we had her. The puppy schools were closed over Xmas. The first experiences at puppy school were of Sasha barking a lot at other dogs and not being allowed near the other dogs. We only went a couple of times and didn't really think it was helping her much. At age 7 months we had someone come and see Sasha as we were worried about her behaviour with other dogs (lots of barking but no growling). They didn't think Sasha was bad. They did say she has a lot of prey drive. They recommended another puppy school which we have been using. Sasha went through the first course. Her obedience is fine but she is more sensitive to other dogs being around her than other dogs at the puppy school. During the classes the trainer gradually integrated Sasha into the middle of the dogs to help with her socialization. They suggested that she needs to be better with other dogs before we can do the next level of the obedience class. We continued with puppy school at the basic level just for socialisation and the trainer is now happy to have Sasha in the next level of the class.

More background on Sasha. We've been pretty careful to reinforce our positions as pack leaders at home to Sasha. We eat first. We don't allow her on furniture or in certain rooms. We constantly command her (sit, down, stay) to keep it up. We position her on her mat once a day (she has been taught not to leave the mat even with distraction).

I've felt that Sasha is being a bully at times. Sometimes after constant mouthing the puppy runs away to hide or stand behind me for protection. If I see this I've been pushing Sasha away and telling her NO. Sasha is pushing her limits far more with this correction than anything before. If I tell Sasha NO about something she may try once again but a second NO does the trick and she will stop doing whatever she is doing. With the puppy I can push her away and tell her NO a number of times and she will still continue to pester the puppy with mouthing and pushing.

When Sasha is calmer and just licks the puppy and sniffs the puppy I've been giving Sasha treats to reinforce that behaviour.

More observations. Sasha has never been possessive about food (i.e. I can put my hand in her bowl while eating). She is still the same way. She hasnt growled or got bossy over food. We've been feeding Sasha first then the puppy by the way to attempt to reinforce Sasha's status.

The puppy is not seeking play with Sasha as Sasha seems to have more energy than the puppy, mouthing him and running after him.

Should I be concerned with Sasha's behaviour? Does she not know enough about normal dog behaviour due to her dog socialisation issues (with people Sasha is fine by the way).

Is Sasha trying to dominant the puppy too much?

Answer
WONDERFUL provision of information! Thank you.

The first puppy class you brought Sasha to did you and her a HUGE DISSERVICE.  Because she was barking at other puppies does NOT mean she should have been kept away from them.  THAT was the beginning (and cause) of her problem.  It is NOT uncommon for the GSD to show over excitement (vocalization, lunging, hyperactivity) even as a puppy toward other dogs.  The person who ran that puppy class is a classic example of someone who belongs in ANOTHER BUSINESS.  Happily, you seem to have found a trainer who has some understanding of GSD psychology (by now allowing Sasha to the next obedience level.)  You have to understand, however, that your anxiety regarding her behavior is most likely contributing heavily to it.  If you anticipate her over excitement and vocalization (and your embarrassment because of it), she will continue to display it.  Your best approach to this is to quickly go to the end of the leash and turn YOUR BACK TO HER, forcing her to reevaluate the situation without whatever contribution you are making.  Do not "correct" her in any way, just remove yourself.  Do this while someone is observing the dog, and do it every time; you should see a huge change in her attitude very, very quickly.  She will show displacement behavior (look around, sniff the ground, come to you to see what to do next, etc.)  Once she offers this displacement behavior IMMEDIATELY, give her a command to "sit", walk back to her, turn back to the other dog, and start over.  If you do this consistently, you will see her unwanted behaviors toward other dogs extinguish.

Regarding the puppy, she is behaving (apparently) with a mix of normal female canine response (nosing, licking, scruff grabbing) and over excitement (learned from her bad experience in that awful puppy class.)  In other words: ambivalence, approach/avoidance, cognitive confusion.  You need to assist her (as you are doing) by rewarding her appropriate displays WITHOUT punishing her for her ambivalence.  First: learn about clicker training; go to Karen Pryor's web site.  Introduce it to Sasha (the GSD is a strong and marvelous candidate for this.)  Reintroduce obedience work using the clicker for ONE SIMPLE BEHAVIOR (this is called crossover training and should take you only a day or so) so she really understands what the "click" means, then USE the clicker to instantly cue her when her behavior toward the puppy is appropriate.  When it is NOT appropriate, interrupt it by getting her attention with an unexpected noise (clap your hands, hoot like an owl, etc.) and then WALK AWAY from her quickly.  Ask someone to observe the first few times you use this technique.  Your removal from her when is is behaving inappropriately with the puppy, coupled with your use of the clicker when she is demonstrating appropriate behavior, should quickly help her to choose the MOST REWARDING response and "think" appropriately (make better choices.)  Any further questions, do not hesitate to repost.