This woman's behaviour and language are ridiculous but I honestly do believe there may have been some miscommunication between her and her cousin. A JFK-KIN guest pass is around $390 and the cheapest JFK-KIN tickets are around $425. It seems that she may have thought that she bought a regular ticket with some sort of friends and family discount instead of a space-available guest pass - nowhere in her rant does she seem to realize or acknowledge that she does not have a confirmed seat.
Not excusing the behavior but her cousin should share the blame for giving the guest pass to an obviously unstable person and not fully explaining to her what she was getting and the rules involved.