Even if she manages to slip through the grip and not be addicted, all of that weight would simply fly back on after she stopped. After your metabolism has been raised to unnatural levels, your thyroid would rebound and try to compensate by shutting itself off until balance is maintained. The same thing happens when steroids aren't used properly. With proper precautions, you can keep some of your gains, but nothing will be permanent.
It's not worth the time, money, or the health just because she doesn't feel like exercising. Make sure you tell her that.