I can't imagine a 2x2 cage knowing how yorkies love to run and love their freedom!
The people that do these things ought to be dealt with and severely.
The only problem I can see with adopting one of that age would be housebreaking her. I've always had mine from tiny puppies. It might not be as bad as I imagine. I know it has been done though, because I know other people have adopted these puppy mill doggies. The one positive is knowing how much yorkies want to please you and using a reward system.
