Rivets, with Graves' it's a diffuse process, not a local nodule, etc, which surgery could remove and leave normal thyroid function. So all the options (surgery, I-131, or antithyroids) will leave her requiring replacement therapy. As things go that is not an expensive proposition -- plenty of people take thyroid replacement for life.
As before, sounds like she is getting excellent care. Don't be detouring into Woo.