Hi and welcome to the GERD forum,
I am sorry ur DD is dealing with so long and still no answers....frustrating I know.....
First, look to ur families medical history...things like thyroid issues can cause sore throat and tiredness....
Reflux can also affect us in many ways...try to elevate the head of her bed so it is on an incline...this way if it is acids getting up into her throat, gravity will help keep them down out of there and down where they belong.
Keep a journal of her foods, drinks etc...look at the list of foods to avoid with reflux in the health pages,,,
http://www.medhelp.org/health_pages/list?cid=236
Make sure u let the Drs know ALL the symptoms she has had regardless if they are not present now as it may help the Drs pinpoint what is going on,
Wishing u and ur DD all the best...do keep us posted on her progress.