Is she taking any psychological medications? Depakote, for one, causes weight gain no matter what. She should have everything checked out, e.g. thyroid, before going extreme on her.
IMO and from experience it sounds like metabolic syndrome. Like others have stated her calories are to low and cardio needs to be upped. I HIGHLY recommend a carb cycling type of diet.
You might also want to take some time to see how much of her weight gain is actually just bloating, I've done some reading about Advair that says along with general weight gain, bloating is a big side effect.