One good thing, German Shepherds are incredibly intelligent and easy to train.
My experience with my Shepherd is he got along with everything as long as I introduced him correctly. He lived in a house with "free range" house rabbits, house birds, cats, iguana and rats. The rats use to ride around on his back lol. We use to visit a friends farm and he was excellent with all the animals including the chickens. BUT he had lots of training, earned his CGC and listened to me very well and had tons of exercise so he was not a bored, anxious dog. As they say a good dog is a tired dog!
My experience with chickens and dogs. I have 2 dogs that are 7 and 4 years old, one is a 65lb Rhodesian mix the other is a 120lb Black & Tan Coon Hound/Mastiff mix- they both are fine with our chickens, our Coon Hound mix is very protective over them and takes his job of chicken protector pretty serious. Even our cats lay in the yard and the chickens will jump on them and fall asleep! Our dogs are very well trained and all of our animals (dogs, cats, rabbits, chickens) are expected to co-exist peacefully and they do. But it takes patience, training and a dog with the right personality/energy.
In my experience I think a dog with a MELLOW personality, not a hyped up crazy anxious dog, with lots of training and lots of exercise and mental stimulation can get along with chickens. But it's definitely up to the owner to put the time in and be responsible. Don't expect to just throw a puppy/dog in with the chickens and expect miracles especially if she is a dog that is physically and mentally bored.
Good Luck!