What is going on with her feathers?

My lovely girl’s feathers near her tail aren’t fanning out how they used to, and I was wondering if anyone knew what was going on?
All the other hens’ feathers are normal, but if you notice in the picture, the feathers at the base of her tail are thin and curled in. She wasn’t like this last year and she hasn’t molted recently.
I checked her skin but didn’t see any critters and her skin is healthy-looking.
Thanks in advance for your help with this!