Princess Jasmine-- I know you are a competent adult-- but in the first post you sounded like you were a little new to the epis. I hope you don't mind- But, I recently had to "fight" for the benedryl that you should also have with the epis (in Philly, in Orlando they were wonderful). So if you have any more questions,let me know. Also, I just want to say like I said before-- try and get more than one epi. Protocol is that the pilot will land the plane if an epi has to be used, but that and getting to a hospital could take more than the 15 minutes the pen gives you. A doctor will give her a prescription for more. And don't forget that benedryl (which often prevents us from getting to the point of having to use the epi). If you have any more questions about bringing epis on board or anything, please feel free to pm me.
Anne is right though about the pen, if your sister can handle it (and I don't know your situation), she should really have the epi on her person at all times-- if you guys are separated for even a few minutes-- it's really important that she has it, and can use it. My son is only 6, but he has a sort of bag that goes everywhere he goes. Right now there's always an adult to handle it, but in a few years, he's gonna have to be the one to carry it around and know how to use it. Maybe it's because we're peanut though, and that's everywhere. Just something to think about.
I hope you guys have a wonderful trip