Your daughter is likely to be suffering from a viral wart
or fungal infection
.Skin lesions can be diagnosed better on close examination.
I don't think that milk has any correlation with the skin rash
.Milk allergies usually present with not tolerating and digesting the milk in the form of vomits and acidic loose motions .
So continue her milk at present .Do get her examined by her doctor so that diagnosis and appropriate treatment can be given.