After thought. If the medicaton smells or has an odor from the bottle, it might be a bad batch or old medication. If this is the case it should be checked into further. Good luck!
It sounds like she is on ATDs. I would believe as a Grave'r myself, its not the disease nor thyroid hormomes (she would have had the order long before starting meds.) and would tend to believe it is the medication or her body chemistry to the meds.
GL,
Just my personal opinion as a thyroid patient.
PTU can do this - less likely tapazole. It's not the Graves, it's the meds -- if it is intolerable to her then ask the doctor to switch to the other (ie, PTU or tapazole) -- also there is a brand of tapazole (aka methimazole) called Northyx that has been useful in this situation for some patients.