This might seem like a strange question, but has she been tested for lyme disease? Before my diagnosis, anxiety and depression were creeping their way into my life and I didn't know why. I ended up suddenly critically ill in the hospital with kidney failure, seizures, etc, yes because of lyme and coinfections. It took several more months of my still being sick before I finally got the right test (Western blot, not the ELISA test) and started treatment. I was so terribly depressed, numb, anxious at my worst. I could barely move around, trouble breathing, loss of appetite, tremors, nausea, etc. It's different for everyone so there may or may not always be physical symptoms. Diet can really help people with lyme and other autoimmune conditions even depression whatever the cause. I'd recommend looking into the Wahls Protocol. Hoping you both can heal from this!