GSD is a breed of dogs in whom the pack instincts are very prominent. GSD puppy wouldn't run to other people or dogs to lick their cheeks, she will stay with you and watch your reaction to a new stranger . Demonstrate to her your qualities as a leader and stroke her, calm her down first.You should show her examples of behavior: touch yourself with your hand, and then the other party - boy/man/dog/puppy - with the gently pronounced words "It's OK" and see what sort of responce it would be from your dog. It is typical to many young females to exhibit shyness. That is so, because they don't feel being a part of the pack. Later in her age she will start showing her protective abilities instead of turning shy, again, don't forget to give her permissive command "OK!" (she would know already), when it's ok for her to jump and bark and play. And, her loyalty must keep her close to you in all other cases.
This is strange and an unfavorable course of action IMHO.
My "shy dog" therapy takes place in Wal-Mart parking lot. I take the dog, her crate, a folding chair, some water, and a bag of treats. I start way away from the door and all the scary people. I sit in the chair with the crate next to me with the door open do the dog can go in the crate. I mark and reward confident behaviors, like the dog checking out a car on the way by, or investigating a stranger at a distance. Whenever the dog is fearful, ignore it. Let her move to her crate if it helps her feel more secure. As the dog shows more confidence, I move gradually closer to the door, over several days or weeks, encouraging people to give her treats as she becomes more comfortable around strangers.
Pretty soon your puppy is the new greeter at Wal-Mart, and strangers are treat dispensing machines.
Many police and military working dogs are female GSDs. Her sex has nothing to do with confidence.
All this is just my way of helping shy dogs. YMMV