Pack a lunch bag?
Sorry to say , but a girl with known SEVERE allergy to banana, milk products, nutts and sesame seeds should under no circumstances trust any food purchased at an airport terminal before boarding a flight shorter then , say 25 minutes.
Every second month I have someone faint or become ill. Always ready to be on the ground within 15 to 25 minutes if needed. Except on the Canary flights were at times 40 to 50 minutes is needed.
I suspect this flight was close to its destination when thing got critical.
A sad thing this is for all involved.
But like all the 1000s crash reports I have read, always something to learn.
Regards
Cpt B