Well she received a dose of reality. Long before all this hysteria about security. People were always being pulled up and arrested for joking about bombs. Bombs on planes is hardly a new phenomena.
I think in practice most people get a heavy ticking off. But she compounded it by repeating it. I doubt if she'll do much in the way of jail time. There was a recent case where an Irish Gaelic footballer made a similar remark. He ended up in court and only got community service. He had to travel back and forth to the US for the court case. I bet he kept his mouth shut then.
You do have to wonder sometimes, what gets into people who make 'jokes' like that?