The only way to open a file on a trial version that has expired is to buy AC.
If she erased AC and reinstalled IIRC the file is lost since the Trial ties the file to that specific installation of AC at that particular computer.
She should get in contact with the reseller to see if buying a monthly license can let her change the file from Trial to full, then when the month expires she can install the EDU version and continue working there.
Eduardo Rolón AIA NCARB AC27 US/INT -> AC08
Macbook Pro M1 Max 64GB ram, OS X 10.XX latest another Moderator