Hi Rose,
I am not certain if the doctors use age as a factor when testing children or not. I know we had our son checked when he was in grade school for other types of autoimmune antibodies and then for Graves’ antibodies once he was in his teens. I personally would ask your childrens’ pediatrician when he/she thinks it best.
Good Luck and prayers for healthy children!
Jan
Online Facilitator, NGDF