So there were no passengers with food allergies on the plane? just a grandmother who is meeting her FA granddaughter after the flight? Ummm.. sounds like the grandma must be a bit nutty (no pun intended).
When i flew (2 years ago) with my severely allergic son, the airline said they are NOT allowed to announce that there is a passenger with food allergies. They are only allowed to tell the 2 rows before and 2 rows behind to not to eat any nuts. They will also not serve nuts on the plane but cannot prohibit from someone bringing their own snacks onboard. A lady couple of rows in front of us did have a nut bar and we POLITELY asked her if she could put it away b/c of our son's allergies (who was on the plane). She did without any hesitation. My son did have a reaction due to the circulated air.. but i just can't imagine why this lady had to move if the child wasn't even on the plane. Maybe she thinks the nut powder will get on her clothes? she's nuts and obviously over dramatic.
yes, she did take it to far. But please don't think we're all like that. It's also possible that the mother of the daughter (her daughter or DIL) exaggerated a bit about the child's allergies