It’s difficult to provide answers, as each patient reacts to illnesses differently. The loss of appetite is concerning. How is she feeling?

Don’t underestimate the potential for a UTI to cause impressive mental symptoms in the elderly, with no urinary symptoms. My elderly mother would hallucinate and see little people all over her house when she had a UTI. I was amazed to learn about this poorly understood syndrome in the elderly. My 94 year old uncle recently became very lethargic, poor appetite, and quite confused before diagnosed with a UTI. It is certainly worth looking into. Can you contact her PCP to order a urinalysis?

My father also experienced the kinds of hallucinations with a UTI that @sepdvm 's mother experienced. Once we discovered the pattern, we also got a little lucky from his misfortune of needing a urinary catheter (due to enlarged prostate), as we were able to see discoloration and low output in his catheter drain bag.

Steroid prescriptions can also be problematic in the elderly. Sometimes steroids are administered to slow down or stop the immune response when patients are having difficulty on an immunotherapy drug, and they sometimes cause sleep deprivation and hallucinations that may be sort of a "waking sleep" behavior when the regular sleep cycle is severely disrupted.

I (non-medically trained) would recommend proceeding with caution using psychoactive drugs like THC (dronabinol or medical cannabis) if mental status is already altered. Something less potent like CBD might provide comfort, calm, and relief without the risk of "tripping out."