My mom is trvling ED 20 on US east internationally on Tue 5 Sept. My question is can she upgrade? If she can, where does she purchase it and does she talk to the tkt counter or gate agent about listing for it? She's very sweet and does not want to be a bother to anyone. She would like to know how it works so she doesnt cause anyone to get upset or add any stress to their job. Any help would be appreciated.