Having Scalp Psoriasis and Sebhoriheic Dermatitis, I’m in a lot of different sucky skin circles and forums, and as you’re aware, our diets influence this stuff huge! I’ve had more luck with both diet and normal supplements than I’ve had with a LONG list of meds and steroids over the years, to the point where unless you knew what you were looking for, or where to look, you wouldn’t notice really that my skin isn’t right, vs prior where you could spot it from across a room.
If she hasn’t done it, she needs both a food sensitivities test, and a stool/gut biome test. Knowing what foods piss off your gut/intestines, and what foods cause an immune response, are needed if you’re going to get around it with diet.
I can tell you, again from being in multiple forums for skin, no shortage of people find out and talk about Carnivore because they read about it doing things for others, and almost nobody sticks with it, like literally almost nobody. It’s just too damn restrictive. Being the meat eating lunatic I am, I was ALL about it when I tried it, made it a couple weeks and almost lost my mind. 4yrs of Keto which is hard enough for the masses was easy, Carnivore drove me nuts.
If she could do it long enough for that light bulb to go off and make her aware that food has a huge hold on this would help, but she’s still be left with not knowing why, only that when she eliminated almost all foods it helped, that’s why the testing is so important. Way easier to pull out the specific things you know your body isn’t happy with, rather than going nuts and pulling almost everything.