Stephen's original plan was for Claire to depart from Eastcliff, while her parents depart from Aurous Hill.

However, he didn't anticipate Charlie insisting on seeing Claire off, so Claire would have to fly to Aurous Hill first.

Be that as it may, she'd be seeing Charlie for the last time once she got on that plane, and their marriage would thus end.

She really didn't want that, but fought off her hesitation for Charlie's sake.

After all, she understood that she wouldn't help Charlie at all