Weak wheezing hen

Cream legbar hen (about 1 year old now) was found in the nest box wheezing like this. I took a look in her throat with a flashlight and didnt see or smell anything out of the ordinary. Her crop feels empty. The rest of the flock is out and about eating and drinking normally.

How can I help this hen? So far I’ve offered electrolyte water and a dark quiet ‘hospital nest’. She’s not interested in drinking.