@YuropFlyer

She lined up in the Foreigner lane, and then was redirected to a special lane. Where they said no.

I will have her call the Chinese embassy in Bangkok when she arrives to see if they know anything. She provided her onward boarding pass, and tried twice, so I can't imagine it be a misunderstanding. She isn't a first-time traveler either, she has stamps from a bunch of asian countries, Europe, and a prior trip to Canada / USA. She's mid-twenties tho, and completed an english-language masters degree program--so she does speak enough english (by Thai standards)

good thing she didn't prebook a tour of the great wall