Yesterday she was even more tired and wasn't interested in much at all, except sleeping. Not surprising, considering she also seemed to run a fever.
Today, she wasn't much interested in eating either. So, we brought her to the vet, which we would have even if she was eating. No lynmph nodes were noticably swelled, nothing in the stomach felt strange, so she got a shot of antibiotic, some fluid under the skin of her neck and sent home.
Seems hardly better, and not much like eating.