that is true but anyway they can't let you totally undefended in another country...some reclamation need to be done because we are not talking about Schengen and domestic flights... And need to be really proved that the strikes literally were the cause of the cancellation if not EU rights applies...
Remember that if you are at the airport inside (no tax area and that) you are not officially in Thailand then you are not overstaying, anyway Lufthansa must give you a solution under European laws (the company is EU and you are EU citizen, that means accomodation and everything should be paid for them)
thanks then from the start she can ask for a 60 day visa? Does she needs something like a insurance or any other COVID test (she has 2 or 3 shots I don't know now)... If she goes out from Thailand, to Cambodia or Vietnam the visa need to be issued again how works this? Thanks!