She's been off feed for 4 months? What types of things are you doing to encourage her to eat? I will tell you that you may receive lots of questions about your husbandry, temps and such. If everything is spot on, at some point she will eat.
My Fat Girl Nico, (who isn't so fat any more), went off feed because she had an infection. I had the vet tube feed her, and I will again this month. I guess my point is to say you may want to rule out everything as a cause of the fast.
PS - don't baby chicks have beaks? Could that be a cause for concern?
Good Luck!