What does the inside of the beak look like? Is there any yellow material or gunk inside the beak or throat? Is there a bad odor? Could she have been stung or bitten by something? Is the bluish area full of fluid? If it isn’t canker or a bite/sting, I would be a little worried about it being cancer. Has she been able to eat and drink enough?
Have you found any resolution to this issue? I have a hen with the same thing it appears. It started behind the eye and has spread to under it. Other than the swelling she is absolutely fine.