Apparently she has a book but it's in a german. I thought I'd share you this truly inspirational woman.
This site has a short article about Bettina Esital who does dressage in the Paralympics. Bettina Eistel - Horsewoman
OMG that's amazing! When I was a kid I knew a boy who was born with no arms. He was the inspiration of our pretty terrible little public school (this was before I was homeschooled) - we were so amazed to watch him draw, write, turn pages and peel bananas with his feet. Nobody bullied him (this was a school rife with bullying) because he was just too darn cool!