We couldn't have been more prepared.
At 4:45 AM, we picked up International Jet-Setting Auntie Carol to be Arianna's Grand Adventure travel mentor.
She taught and re-taught. And wrote up some "cheat sheets". Decoded some lingo. Disclosed every airport mistake she herself had ever made. (they were impressive!) When the "crash course" concluded; the child had to check herself in while we watched her from the Tim Horton trenches.
They checked her in anyway. Humble little EF Tours economy traveller. I think it was her good looks and obvious charm.
She's first class all the way. (in my books...)
Auntie Carol sidled up to First Class herself, once we were sure they were indeed loading her up with boarding passes and not selling her to a pirate ship in Somalia. She got herself a pass to walk Arianna through customs and teach her a little more stuff about how to read airport signs.