Silkie with suspected wry neck

[Swbertrand1]

This makes me think that there is much more going on if she is not responding

Wry Neck does not "sort itself", and Silkies are prone to the condition. It's caused by one of three things in almost all cases:
a) head injury
b) vitamin deficiency (B1 & E)
c) Mareks
Have you treated her with vitamin therapy yet? You've said it's been 5 days, but unless you treat the symptom, the bird is not going to improve. Feeding her will keep her alive, but until she can feed herself, the condition will persist.

 

[Chickarama1]

Yes, I have been treating it with vitamin B1 and E and no change which indicated to me probably Mareks… incidentally I have a group of vaccinated silkies who were fed the same and are currently fit and well so I suspect this one has been very unlucky or maybe has an underlying health condition which has compromised her immune system.

 

[Swbertrand1]

Since you've had Mareks in your flock previously, then I'd lean that way. Like Eggcessive said, it will stick around for weeks, months, sometimes even years... :-(