She is Swedish and I am American. The process to legally change her name and get a new passport may be quick in Sweden. So quick she may have a new passport and a new legal name within a week of our marriage before we flight back to Thailand. So she may have a new legal name by the time of our return flight to Thailand. Since the flight is international, she needs to show her passport. Most airlines in the world would change the name with the proper documentation. I have done my research and most airlines do that. Also, Aviation Law which is the law of international aviation that the entire world follows says nothing about it being illegal to change the name of a ticket. Airlines don't allow you to transfer the ticket to another passenger because they may make less money. I don't see why the same person cannot update their ticket, especially since this was not an option when booking the ticket.