I am going to be the negative Nellie on this thread. I think that you should get someone with a heap more experience than yourself to work with this horse. You have said things that make no sense to me. You have said that she is extremely head shy but she must have had some kind of halter on her when she got to you, she must have been able to be lead because somehow someone got her to your place. I'm pretty sure she would have arrived by some means that required catching and haltering I doubt she teleported to your property.
You have said that you have no experience which is a great thing to step up and admit from the get go BUT admitting it, doesn't change the fact that you have No Experience! Honestly I think your horse knows a hell of a lot more than you do and is having the time of her life training you. Get an experienced horse person to start with the horse, your job will be to watch and learn. Right now it is plainly obvious that you have bitten off more than you can chew and have no idea how to determine whether your horse is being disrespectful or has holes in her training.
I am not trying to be mean, I do wish you the best relationship possible with your lovely mare, PLEASE get some help!