You have to ask yourself, is there any possible harm in the advice? If not you should strongly consider following it. Avoiding milk and red meats just seems like a good idea with all the hormones they give the animals. If you want her to have dairy, consider something like yogurt which has been pre-digested by yeast. Personally, as soon as I found out I might have cancer I stopped eating red meat. Now that I know I have cancer I have switched to soy milk and removed processed sugars & honey from my diet. In the end I know it won't hurt me, so with the possibility it might help save my life I consider it a smart choice.
Now a harder question would be what about layatril? The arsenic is locked in, so taking a small dosage to prevent cancer probably makes sense. What is the harm in a few apricot pits each day on your salad? But if you have cancer, the cancer cells break down the layatril. That kills the cancer cell (good), but then some of the arsenic ends up in the blood stream (bad). Is it a wise idea to take large amounts layatril to fight cancer? Probably not if you have any other treatment options available. There are people who swear layatril saved their lives, and others who claim it will kill you from arsenic poisoning. Who do you believe?