I think she will eat, but not before she completely stresses you out! If she was a puppy mill dog, I wonder if she wouldn't prefer eating inside her crate? Maybe it just seems to "exposed" eating out in the open? I don't really have experience with puppy mill dogs, but it's just an idea that occurred to me, based on what her prior life was probably like.
These are rough days, but I think a positive, confident attitude toward it all will go a long way. She's definitely going to take time to trust and get used to "the good life." And she apparently ate all those years in the mill, so I would feel pretty confident that she will get it all figured out, barring any sort of health issues that could cause the problem.
I know how scary it can be when they don't eat. We had a dog sitter stay at our house last summer when we were on vacation. Daisy slowly stopped eating and even when we came back, she still refused to eat. I'll never know if it was because she was upset, or if she had tummy issues. She wasn't eating quite like her normal self a couple of days before left, so I'm not sure if it was something brewing before, or whether it was the stress of us being gone.
When we got back and saw she still wouldn't eat, we took her to the vet repeatedly, did an ultrasound, barium series, blood tests, etc to see if she had an obstruction or other problem. We never found out why, but I eventually got her eating again using the Satin Balls that are often mentioned on this board. That did the trick. Over the course of a few weeks, I got her back on her regular food. So I know the anxiety you are feeling very well. The vet tried her on all the normal canned prescription diets and she would not have any of it. He kept her overnight for 2 whole days and nights because I think he didn't believe me that she wasn't eating. He said he had 5 kinds of canned dog food lined up in front of her and she wouldn't even take a sniff. That's when he got really worried. He said eventually we would have to start force/tube feeding her. That's when I tried the Satin Balls.
Good luck and hang in there!