Forgot to mention that anger can also be a sign of bromide. Salt is necessary to help it move out of the body.
Though I'm not sure if the amount of Iodine she was taking is enough to stir up too much. 6.25 mg isn't really that much.
Anyway, she might try 1/8 teaspoon of the salt in plenty of water or the salt in capsules and see if that would help. Also liberally salting her food.
Another option might be the Adrenal Miracle Mix--do a search in the CureZone search box. I don't remember the exact formulation, but it has salt and postassium in a larger quantity of water, so maybe that would be more tolerable.
I would have her try until she finds a way she can take it, particularly if she's going to continue with the iodine.