Normally I would just say put the hard dog food down, and walk away, dogs won't starve themselves.
But your dog seems to be very depressed, and I think you will need to get her depression under control for her to go back to her normal eating habits.
Has your vet suggested any sort of therapy for her? And no, I don't mean laying on a couch talking with a shrink
BUt I mean spending times with other dogs at a dog park, extra exercise, doggy socialization classes, or even behaviour mod classes?
Dogs can go through bouts of depression like any human can, so all the drastic changes in her life seem to be really effecting her.
Will your girl eat soft dog food? A lot of times only eating a soft food diet, wreaks havoc on their teeth, but as long as you are mindful of giving her crunchy bones and treats she should be okay.