If she is below the age of 16 or 15, you can use a school ID that the school can print off if you ask. The best thing to have though in my opinion is a state ID card. You can get these ID cards at the DMV. Hope this is helpful for all!
You'll have to talk with a boarding agent, but most likely you can't. They usually only allow it if you are escorting an unaccompanied minor (13 and below). But good luck!
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