I agree, get rid of the contraption, they are no replacement for hard work.
As was mentioned, she was bred to have a high head, its not likely that's suddenly going to change. My arab has a high head, I like it, and work with it. It actually has become strange riding something with a level head set, I keep wishing they would lift their head up.
You have three choices, either work very hard to try and get her to naturally drop her head, Accept that she has a high head and work with it or get a different horse.