How severe? Does she carry an epi pen with her in case of severe reaction? Does it affect her airway or is this a rash reaction? Mango is a fruit here in Jamaica and in can be overlooked by kitchens as they use it as garnish and in sauces and they aren't used to watching for these thing and some foods are made ahead of time with no recipe. Make sure she carries benadryl liquid if she doesn't have an epi pen or ask about one before you come if you feel it could be life threatening! See my contact info under MARKET for when you arrive or email dates on my webpage just in case. Nurse Beth Comforts of Home Nursing Services