Is she alone? Chickens like company. How much space does she have? While some breeds can stand less space, it is more humane to give her as much space as possible, and provide some sort of enrichment. A chicken toy can be something as simple as an apple, or as complicated as a parrot toy designed to release food when prodded. Give her a place to dust bathe. Again you don't need an acre of dirt, and as some of the members discovered, a flower pot with dirt (clean sand preferred) is favored by many chickens.
Remember, chickens like to be busy, and one of the cheapest toys I've seen was a two liter bottle filled with scratch feed. The clear plastic bottle had small holes that released a few morsels of grain when the chicken pecked at it. I've seen them hanging in pens and I've seen them laying on the ground. This simple toy makes the chicken work for its food and kept the bird busy. And as with any toy, it must be kept clean. Make sure the feed is free of mold and is fresh. Since you only have one chicken an 16 oz recyclable water bottle will be perfect.
And if you can't afford another chicken, place a mirror near her living space so she can see herself. She will think there is another chicken nearby and hopefully give her comfort.
..... Maybe she wants to get out?!
