If it's bad enough for her actual skull to feel different, I'd probably just cull her and put her out of her misery - and then cut the head open to look for signs of an injury, to make sure is't not a disease.
If we are talking a swelling beneath the skin making the skull feel strange, she might stand a chance.. But she sure does look pretty dead already in that picture, I don't think her chances are good. Coturnix are pretty resilient though and can get over many things you'd think impossible, but unless she can eat and drink she's pretty unlikely to survive - even if you hand feed her.