It is tricky to know whether she is sick with something like coccidiosis or worms, dehydrated, or something else. Do you have any Poultry NutriDrench or electrolytes with vitamins at home to give her a few drops? Offer some scrambled egg chooped up, and put a little water in a small cup of chicken feed for her. Watch to see if she will eat and drink.
She might be feeling puny as gets ready to lay. You can check to see if she has a stuck egg by inserting a finger inside her vent an inch or so. Check her crop as well, to feel if it is empty and flat, or full, hard, or puffy/boggy. Look over her skin under the vent and her belly for lice or mites.
Symptoms of coccidiosis are lethargy or sleepiness, standing around puffed up, poor appetite, runny poops with mucus or some blood, and weakness. Corid (amprollium) is something you can get at most feed stores to treat for coccidiosis. Dosage is 10 ml or 2 tsp of the liquid per gallon of water for 5-7 days. You can also give a couple of drops orally of the undiluted Corid twice a day.
