Not Eating
Melissa,
Sorry to hear about Crush.
Try a dead fuzzy or hopper mouse to get her interested again. I know they are small for an adult corn, but you have to get her back to eating something, if it's been 3 to 4 months. An adult rat is too big.
If she refuses to eat a fuzzy mouse, or a hopper, then you're going to have to take her and literally Push the small morsel down her throat. I would be willing to bet that once the head is in her throat, she'll swallow the rest on her own. If you cannot do this, then you'll have to take her back to the vet's and let the Doc show you how to force feed her.
I lost one corn by not doing something when I should have. Then another stopped eating for some reason. After a few weeks, I sprang into action and got mad enough to push a pinkie (Live) down his lazy throat. He's eating now with no problem. I kept him on small prey for about three feeding times after that and worked him slowly back to a normal size portion.
There's a whole list of reasons why a snake will quit eating, but, if you have been through that list and have eliminated the most obvious, e.g., shedding, brumation, and so forth, then it's time to act.
Good luck.
Gregg