I haven't read the other posts, so I don't know what's been said already, but, from the few ISFJs I know and the things I've read, ISFJs are relatively avoidant (denial and stubbornness), so I don't think directness will really work very well. Although straight logic probably won't work the best either, you may want to volunteer to bring her to an allergist. If she claims it's allergies, then say you are concerned about her weight and the possibility of allergies causing her weight to drop and that you would like to see an allergist with her so that you can together help her find solutions (types of allergy-safe nutritious foods she can eat to maintain her health). Really verbalize all of this (even if you don't completely believe it). When you do go to the allergist, they will test for all allergies and either identify those allergies so you can help her to refocus what she eats (rather than avoiding everything and losing so much weight) to a healthier physical and mental state or you can rule out allergies and know for sure if you are dealing with anorexia. If it is anorexia, then you will have to approach it differently, obviously. But, regardless, it seems like maybe tough love without much confrontation (if that makes sense?) will help? If you have done the allergist thing and whatever already and are pretty sure it's anorexia (which it may or may NOT be truly--but sounds like it may be because of the alcoholic father... maybe it's her way of regaining control of her life, which is common grounds for anorexia)... maybe tell her that you are very worried about her and say that you know her husband is difficult and controls her life with his alcoholism, but that her hurting herself is not going to help (don't say she's anorexic, but just comment on the fact that even if she has food allergies as she believes she does, dropping her weight so low, as she would know as a person with knowledge of health-focused alternative medicine--say that too, confidence boosters--is damaging to herself. Tell her you want to help her/encourage her to explore allergy-sensitive foods that will be nutritious and help her gain control of her health--show her that her low weight and health is actually making her lose control of her SELF and that taking care of herself will help her control her own body and sense of self in ways no one else can--refocus her sense of control and remind her to ask herself "what do <i>I</i> want and what have I done for <i>myself</I>--it's so easy to get wrapped up in the needs, wants, and control of an alcoholic in one's life--remind her to focus on herself and that it is okay and even healthy to be self-focused to a degree--to take care of yourself is to take care of others around you because they can't do it for you and they care about you). Sorry for the rambling--just some thoughts from experience--hope this helps!