Although most young people recover quickly, doctors are seeing some children and teens with lingering fatigue and other chronic problems.
For least viral mayhem, we need to keep our immune system strong with Vitamin D (supplement or sunshine), Zinc (supplement), and Beta glucan (in nutritional yeast). These things don't get much press, because they are inexpensive. However, the medical research demonstrates their efficacy. Google them.
I wonder if Vitamin B12 injections could help her with those symptoms.
And it's going to get worse if schools open up too quickly...