I got her a 'Relief Band' and she now flies without airsickness
We suggested these some time back in this thread, and I have also mentioned them in other threads. Also known in the UK, I believe, as "C-bands" ( ?? reference to "sea" - sickness ! ! ). Said to work by acupressure, but I think suggestion and constant reinforcement (you are aware of their presence all the time) are probably more important.
MOST importantly - NONE of the potential hazards of phenothiazines.
Period.