I haven't read all the responses so I'm sorry if this has been repeated several times. I did read that she had a spinal tap which would have ruled out meningitis, my first thought w/ the fever, h/a, sensitivity to light, etc. I am wondering if Lyme Disease is prevalent in your area. Unfortunately, here in the Northeast it is. My 9 year old son was just diagnosed with it 2 weeks ago, and one of his classmates (who he hasn't spent any time with this summer) was diagnosed yesterday. My son had fever, headaches, loss of appetitie, fatigue. He did get the classic bulls-eye rash but not everybody does. Just a thought.
Otherwise, I hope she is feeling better and you get your answers soon. Sounds like you are dealing with many things right now. Take care of yourself too.