Whats your story on adopting a dog from a puppy mill?

I just need more info on how the rehabilitation process went. We have no kids and my BF loves dogs but is not an expert. My roommate only has had experience with having one stray that was a normal dog. There was a raid and I want to adopt one of the 370 toy American Eskimos that was taken. She is a year old and is about 13 pounds. Right now she growls and snaps when you pick her up and cowers in the corner when you put her down. She has come up and sniffed my finger on the first meeting. I have read many articles and have handled this breed and strays before just never a puppy mill dog. I know what I am in for. 6 months or more of rehabilitating the dog. What are the odds of her being a good family pet?