Ummmmm Fiji,Great, My feeling is you are correct in your assumption of Allergys,
Rashes and Runny nose are
symptoms of Allergy, also.Get her to make some notes of what she is doing, eaten ,prior to the incidents check the stuff you spray around if you spray Bug spray I dont know your climate ,do you get Bugs in the Winter is there any specific virus around then, the search engine may help, allergys are hard to track,it means eliminating things one at a time, then re introducing them.