My wife is the same way. Usually, though, she won't barf, but instead sleeps. And sleeps....and sleeps. Non-drowsy Dramamine helps her greatly. I've tried to teach her to visualize and pretend she's driving. She won't do it, but it cures me anytime I get a little motion sickness. I did it once in an airliner that was in severe turbulence for over an hour. People were throwing up all over the airplane. It was a choir of moaning, groaning, crying and even some screaming whenever the plane would rise or fall. I was starting to get sick and just looked forward and pretended I was at the controls. (I'm a private pilot, so it was easy to truly visualize flying the aircraft). My sickness went away. Nobody wanted their dinner, so I had a little airline food feast. Of course, it made them sicker to see me eating!
Anyway, another thing to do is to not let your head fall backward. Keeping it forward helps. It won't cure or prevent, but it will lessen the severity. The Dramamine works well for my wife, though, but she has to take it an hour or so before the ride, or boating, or flying.
I hope this helps. Everybody is different, so mileage may vary.
