Well, I don't know what to make of this but, here's what I've noticed.
DD is anaphylactic with nuts, but the 2 that are the worst for her (can kill her) are pistacchios and cashews. And coincidentally (?) these are the only 2 nuts that DH and I would buy and eat at home, while i was pg (well before then too... but yes, i did eat them during my pregnancy.)
So i don't know, but we just don't have any nuts or anything containing nuts at home now because of DD, so I was a no nut zone during my pregnancy with DS.
Of course DD's allergy specialist who tests her every year, told me to book in to see him as soon as DS was born, so he can test DS as well as having a family member with a severe allergic reaction means it is very likely that he too will have it.

Has that shed any light on anything for anyone?
Basically, I am concerned that maybe she is allergic to the 2 nuts we ate most, because i ate them during the pregnancy (though admitedly, i wasn't living on them per se... )