First, BLESS you for your loving and concerned and thorough post - that in itself is proof that you have all it takes to heal little Zoey
. Second, I agree - posting a Breeder Review would be very helpful. If it were me, I would also be on the phone pronto to the vet who signed her form - and I'd be letting him know that I'll be contacting the licensing board - I'd be asking that vet HOW he signed a release for this baby when clearly she was a mess; I would file a formal complaint w/ his jurisdiction's licensing board.
As for little Zoey - she will come out of her shell. Clearly, she was in an environment where she did not have any reason to feel safe. Over time, she will learn that she *is* now in a safe environment. A small thing you can do is take a doggie size bandana and rub it all over you and your other dog and tie it around her neck (ONLY when you're in the house, otherwise not safe to have on neck - then lay it in her bed) so your smells are right there by her nose. You could also think about buying her a D.A.P. collar - that's a collar that emits a calming pheromone and might be extremely helpful to her.
Have you tried playing with her? She won't play at all yet? Will she have a chew yummy/treat? Little pieces of cereal from your hand?
A GREAT book I'd recommend is called The Loved Dog by Tamar Gellar - she is Oprah's trainer - and Tamar understands dogs like no one else - and refuses to use any sort of negative reinforcement whatsoever. She also talks about how to help dogs come out of their shells, if they've been mistreated. I adore her and think she is the best trainer out there.
Try not to worry - dogs are essentially made of love, so when they learn they're in a safe environment, their essency just naturally emerges - it just takes a little time.
Please keep us posted on this special baby.