Today I flew JetBlue with my peanut/tree nut allergic daughter. As per their policy, they did make an announcement asking passengers in our row, the row in front and row behind us not to consume nuts.
I booked the flight two days prior as a last minute trip and did not note her nut allergy in the booking. While the crew did make the announcement, and were very nice, they weren’t happy that I didn’t note it in the reservation. So this a reminder to make sure you alert the airline to the allergy when you book.