Dear Sue,
For quite sometime I was displaying the same symptoms as your daughter. To cut a very long story short I must have seen over 50 doctors about this, including GP's, natural health practitioners of every persuasion, psychotherapist, hypnotherapists, counsellors, EFT therapist etc etc. My body kept showing signs of panic and stress where my life had no such stressors in them. The only stress I arguable had was not knowing what was wrong with me - that is hugely stressful. Magnesium and BVitamins as well as Essential Fatty Acids kind of lessened the symptoms but it was always there in the background.
Finally after 5 years of hell (and even starting to believe that I was damaged goods) I found a Naturopath who had her thinking hat on and after a couple of very simple tests (mineral check, full thyroid check and Cortisol/adrenal check) - I am in fact NOT full of Candida, NOT saturated in Mercury and Lead, NOT dysbiotic, NOT hypothyroid ... or any of the other long list of rubbish that I was sort of diagnosed with.
I do have extreme adrenal fatigue and am now (finally) on some lovely herbs and supplements and my life is coming back to me.
My advice:
GET THE FACTS - although there are some great alternative therapies out there the best in my opinion is where east and west meet, where modern and ancient healing come together - A Naturopath does just that : they test you and apply the appropriate therapy.
Wishing your daughter a great recovery:)