Hi J., I have a four and half years old daughter and she goes in and out of allergies where she will get a rash and then her face, eyes or lips will swallow up, she has this problem since she is 1one month old. the doctor gave me the twinjet pen an emergency injection and also children’s Benadryl I take them every where we go she is now allergic to Sesame, Pork, and Cardamom so you can imagine I think you should ask her allergist Dc. About the twinjet pen and you should take the Benadryl with you in the plane that’s what I always use first if she gets worse I use the pen, also take Clorox Wipes and wipe the sit and everything she will be in contact with in the plane and take snacks for her to be on the safe side. Good luck on your trip.