Might she just be heat stressed?It is hot, moist and muggy where I live.
Any other birds acting off, or have loosey poops from drinking more than usual?
Electrolytes might help.
https://www.backyardchickens.com/articles/aarts-extreme-weather-spiel.75893/
Where in this world are you located?
Climate, and time of year, is almost always a factor.
Please add your general geographical location to your profile.
It's easy to do, and then it's always there!