I'm not sure how I managed to miss you and your story about Chloe. It sounds like you have been given some great advice already. Did you happen to read this article?
http://www.yorkietalk.com/forums/tra...nt-advice.html
It touches on all different aspects of helping a puppymill or even a rehome come out of their shell. I didn't see anyone suggest sitting on the floor with treats and allowing Chloe to come to you. If you associate human contact with food it is amazing how they will begin to come around. When you are sitting and she approaches allow her to tough you and fight that temptation to reach out to pet her.
I hope everything works out for both of you. My Bogey was very timid when I first brought him home and he is the best of my three now. It took months of work but little by little he turned into a wonderful little lovebug.