Based on the chicken health handbook, she actually might have coxy. It says that there are two different types/strains of it: cecal and intestinal. The strain that affects the cecum usually appears in chicks that are 4-6 weeks of age, but maybe earlier or later. Droopiness, huddling with ruffled feathers, deceased appetite, pale skin, retarted growth, and bloody or pasty droppings are the main symptoms. It says that a postmortem examination will reveal a bloated ceca filled with boody or cheesy material, and pale breast muscles. The mortality is usually high, and it appears suddenly.
The intestinal strain can occur in chicks that are 3-5 weeks, but can occur much later. Again, droopiness, huddling with ruffled feathers, disinterst in food and water, and weird poop are the main indicators of it, but it also says that in pullets reaching maturity, thin breast, weak legs, a drop in laying and diarrhea are also common. It says that mortality is usually low, but it is still very contagious.
In order to not plagarise, almost everything in this post are the words of Gail Damerow from the chicken health handbook, not mine.