Have you seen a dermatologist for her eczema? It might not be an allergy-related issue at all and fiddling around with diet might not be the ultimate solution either. But you really need to make the effort to have her properly allergy tested. I know it is a huge PITA to fight with Dr to get them to listen to you, but it really needs to be done if you are to find out for sure what is her trigger. At her age she does not need dairy as a diet staple either. There are plenty of other food sources that are calcium rich that you can give her instead and totally avoid the dairy altogether. Personally I think non-fermented soy is evil and should be avoided at all costs.