Thank you, KiwiAussie. That is a very interesting article.
Since that is treated as an "extension of stay", my assumption is that she would NOT be allowed to work. This may be a means of buying her more time if needed (she has also applied to CM International University) so we another "fall back" option (assuming she is accepted, she can extend based on Education). So, I think we will be safe allowing her stay long enough for the Thai ID and passport solution.
Then, it looks like I'll get a Siem Reep and Angkor Wat vacation with her to clear out her USA passport.