Oh I know!! I was thoroughly irritated and feel like I'm back to square one. Has your DS ever reacted to peanuts - on the plane or otherwise?
Thankfully we Never had an issue with flying.
Once when he was younger we took him to the Ringling Bros Circus, which was in a covered building, he sneezed and coughed the whole time we were there. I realized after too long of a time, that there was peanuts shells all over the floor. I left as soon as I put 2 and 2 together, this was well before I was aware of how and what we should know about the peanut allergy.
When we were in my SIL's home she had an open container of peanuts, which I didn't know. My son was coughing the whole time we were there. I went to my DH and told him we are going to have to leave, because DS won't stop coughing something has to be bothering him. That's when he told me he say the peanuts and had just put them away. Once he did that the coughing stopped.
So it seems as he gets the cough around open peanuts and the DR said he's trying to catch is breath. They were the only 2 episodes we had with being around peanuts and that was at least 5 yrs ago from the last one, which was at my SIL's. Leaving the area seems to stop the reaction of sneezing and coughing.
We had only one full blown reaction which he ended up with a hospital when he was 18 mos old. He found a peanut butter cup in a lunch bag and ate it. The bag was so old he wasn't even born yet, the last time it was used. So we had no clue it was in there.
He is now 11 yrs old and I am just as scared today as I was at 18 mos when it hit me he really is allergic.
How would he react today with open peanuts around him, I don't know. hopefully the cough would be the only reaction and my warning to get him out of there.
How have things been for your DD, flying the first time with him was nerve wrecking, but our airline always worked with us and helped in every way they can. a few times we even have an attendant check on us all through the flight.