Should i be worried?

[Johnn]

My chicken was loosing loads of feathers i got her on christmas eve and shes and ex battery hens but as i was looking i found a air sack on the back of her neck, it has no fluids in and is sking colour, it dosent bother her in anyway, will she be ok?

 

[teach1rusl]

Is it possible she was losing lots of feathers because she was molting???
I don't know about the fluid sack, but as long as she is behaving normally (eating/drinking/eliminating/moving about) and doesn't appear to be in pain, I wouldn't stress too much about it.