Feather mites eating tail feathers only?

[My Three Chicks]

My 2-year old Olive Egger's tail feathers are looking very raggedy. Only the tail feathers though. The rest of her is normal and full. And only her out of my 6 hens.
They don't peck or pick each others feathers. And I've never seen her aggressively preening her tail feathers (or preening them at all).

Is this feather mites or could it be something else?

She's well and normal otherwise.

 

[oldhenlikesdogs]

What do your roosts look like. Could be she's rubbing them on the wall or even on the fencing. They look more broken to me, but I haven't dealt with feather mites before.

 

[My Three Chicks]

What do your roosts look like. Could be she's rubbing them on the wall or even on the fencing. They look more broken to me, but I haven't dealt with feather mites before.

Here's a pic of their roost at night. The top row is close to the wall. But I can't imagine there's enough rubbing to cause the damage. But it's a thought!