We flew round-trip on Jet Blue from Tampa to D.C. in September of 2016 with my 11 year-old son who is anaphylactic to many foods including peanuts. After researching the snacks served on board, we were happy to find they did not serve any free items that contained nuts.
A couple of items available for purchase contained tree nuts as ingredients (nothing warmed), but it wasn’t enough to alarm me. Our family sat in the second row both ways, and the flight attendant in Tampa told the rows in front of us and behind us to refrain from eating anything with nuts as there was a person near them with a peanut allergy. She was very supportive, no nonsense.
In D.C. we were late pushing back from the gate, and the flight attendant was very busy. She did not make the announcement to the rows around us. At this point, the passengers in the rows around us were falling asleep, so I decided to wait and see. Both ways, people only ate the provided snacks (which even included Skeeter nut-free cookies). It was a good experience. I did come prepared, however, with plenty of Epipens,wipes, and a particulate mask just in case.