Odd Behaviour in my GSD Bitch. - Page 2

I agree, she sounds like she is unsure of her place in your pack.  If she viewed you as pack leader she would never pull a stunt like this.  Correct her sharply and completely.  Don't just avoid.  Let her start her little stunt, snatch her back and smack her under her jaw, hard.  It won't harm her and will get her attention.  If you don't get her attention, you didn't smack her hard enough.  You need to get her attention away from the other dog and onto you and then you read her the riot act.  Put her in a down position and stand on the leash so that she can't get up and let the other dog walk around her.  That will get the point across to her that she is to be calm in this situation and that you are on top of it.  She may be reading your feelings (fear that oh no, is she going to attack again) and reacting to it.  A dog can sense when you are fearful but they don't know that it is the situation you fear...they will read that you fear the other dog and react.  I see gentle leaders on your dogs...get rid of them and use a pinch.  Good luck!