Well, she might be confident. Flying can be a bit nerve - wracking, but a confident plane girl would handle all the situations on the plane smoothly, whether it's dealing with difficult passengers or unexpected flight delays. Also, she would be intelligent enough to understand safety procedures and communicate them clearly to the passengers. In addition, she could be adventurous, loving the idea of traveling to different places all the time.
She could be kind, like always being there to help passengers find their seats or get them something to drink.
One characteristic could be her grace. A pretty plane girl would move gracefully in the narrow aisles of the plane. She would also be patient. There are so many types of passengers, some might be very demanding, but she would patiently listen to their requests and do her best to meet them. And of course, her physical beauty would be enhanced by her warm smile that she gives to everyone on board.