Look into Hashitoxicosis. She has Hashimoto's with out a doubt occasionally you can spawn off Graves too or vice versa. My mother and Aunt had both Graves and Hashimoto's. I was diagnosed just hashimoto's... but I started meds and went hypert real quick. I have went back to half meds.. but still have hyperT flares. it is common in Hashimoto's. It is scary and not fun. Here is some of my research and finding in this mess. Thyroid care concerns around the world - week 2
Look over this post and look into the Hashitoxicosis. In some cases only thyroid removal will help stabilize things and allow you to optimize. Now what about you or her grandmother's? Any thyroid issues? Have you checked? AIs are familial dependent in most cases. There is an 80% chance of inheretence from a maternal carrier to a daughter and 20-40% from mom to son.