Thank you everyone. As to the person who said "let her see it with her left eye", she usually does and spooks anyway. I do tell her to knock it off as she tries to wheel around or half rears. I try not to anticipate that she's going to spook at school buses or cars with trailers.
I rode her the other day and a truck pulling a boat was coming our way. I let out a breath that I didn't want to hold and the person in the truck stopped dead in the road. She never even took a second look at it, not even when we had passed it and the guy resumed his journey.
I do appreciate all the feedback.
"When you're young and you fall off a horse, you may break something. When you're my age, you splatter." -- Roy Rogers