This is a little tangential, but as someone who had chronic URIs as a kid (although not so much the ear infections kids get now), has your daughter seen an allergist? If she's allergic to dairy, she's likely allergic to other things too (both inhalants and foods). Treating all her allergies, by immunotherapy and avoidance, is likely to help. And a doctor's diagnosis will probably help her other relatives understand the importance of avoiding certain foods. Although even if it doesn't, whatever you can do to reduce her allergic load will help.