Yes I agree, a very stupid thing to say
, but I think jail is a harsh. Maybe more appropriate to remove her from the flight and have her buy another ticket at her own expense to fly back, plus if delay costs then charge them to her, she should be able to pay them back in maybe 10 or 20 years after she has graduated!
these type of incidents are relatively few and far between but you need some sort of deterrent so that people will be well aware of the consequences. Jail time is excessive but inconvenience the culprit the way they have inconvenienced the rest of the passengers and crew. Waste her time and money and see how she likes it
