Nice coop
My guess is your Hen just needs some R&R, and she'll bounce back soon, as long as she's not dealing with an infection. They are pretty resilient birds.
It's miserable hot here too, so I feel your (and your birds') pain! My Guineas always like an area of their dust bathing areas wet down around noon so they can churn it all up and stay cool all afternoon).

My guess is your Hen just needs some R&R, and she'll bounce back soon, as long as she's not dealing with an infection. They are pretty resilient birds.
It's miserable hot here too, so I feel your (and your birds') pain! My Guineas always like an area of their dust bathing areas wet down around noon so they can churn it all up and stay cool all afternoon).