Sorry didn't answer really your question , you can read this:
http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=/healthatoz/Atoz/ency/thyroid_nuclear_medicine_scan.jsp
Probably your daughter have a nodule, but FNA would be more accurate. I have a cousin that had a thyroid cancer (one nodule), she was 9 years old, and she did FNA and scan.
Does she have any nodule? (any FNA?) , any symptoms? or they suspect something on her Pituitary gland ?