Maybe this isn't "ethically pure", but perhaps the nonrefundable ticket allows her to save some face, if it comes to that....

"You're going!!!!??? I can't believe you're being so selfish as to go when I'm having a root canal/problems at work/insert crisis here ..."

"Well, honey, the plane tickets *are* non-refundable ....."

"Oh .................. well, ok then."

Who knows, but maybe.

Hairdog: I think empathy gets a bit easier when you commit yourself to a course of empathy *without* surrender.

"Show me a completely smooth operation and I'll show you someone who's covering mistakes.
Real boats rock." -- Frank Herbert