So just an update: I just got back from taking Diedra to the vet (Avian and Exotic Clinic of Monterey Peninsula), and the prognosis is good for now. I gave the vet the whole back story, and she said she checked out fine. I told her that I was worried of neurological damage, or possibly the rat rotting in her stomach due to the heat (had eaten 2 days prior to incident). As I thought, no way to tell for sure about brain damage except for observing her behavior over time and seeing how it relates to her behavior prior to the incident. She has most of her head-shyness back, and seems completely normal and healthy otherwise.
I decided to get blood work done just for my peace of mind to check her liver and kidney functions, so I will have those results by Monday. If the tests come back with issues, they said they will start her on a fluid treatment, but I'm doubtful it will be needed.

On a side note, although they are extremely knowledgeable and experienced, they said she should be eating mice and not rats (eye-roll) because she looked fairly large for her age (because she is only 4 days into digesting a 65g rat). She was born on October 6, 2010, and is currently sitting at 604 grams, partially full. Thank you to those that gave me kind words! Will keep updated.