I agree with Totie. She must be miserable.
I had an over active thyroid (hyperthyroidism), that is too long to weigt for an appt! The doctor is crazy! The rapid heart is a major issue in itself. You don't want her to go into cardiac arrest. Not scaring you, but I had the exact same symptoms as your daughter. I went in to get a CT Scan, and when they saw my heart rate was 140 just sitting, i was immediately hospitalized. Is she currently on any medications? Her weight is another issue, please call them and ask for a quicker referral, the over active will cause havoc on the body, trust me....
Tell the doctor there is no way she can wait that long!