Hi --

If the baby has consumed milk in other forms (cheese, yogurt or ice-cream,
for example) without ill effects, then I'd be inclined to suspect seasonal
allergies. If that's the case, suggest that your sister continue
breastfeeding until the seasonal allergies pass, and then try straight milk
again.

If, on the other hand, the dairy your niece has consumed has been tiny
amounts cooked into other foods (such as bread or cake) then she might want
to continue nursing and then consult with her pediatrician.  A blood test or
scratch test might be in order, or a supervised milk challenge.

I would not try out nut milks in a child this young.  An allergy-prone child
shouldn't consume nuts until she's old enough to *complain* of early
symptons of a serious reaction (itchy throat, trouble swallowing).  Those
early complaints can buy enough time to get to a hospital.

I hope these thoughts help,
--Beth Kevles
  Eating without Casein webmaster
  http://web.mit/edu/kevles/www/nomilk.html

Nothing in this message should be construed as medical advice!!!  Consult
with your own doctor about matters of concern.