I am a big believer that animals are a lot smarter than people normally give them credit for, but I won't get into that now. :)
I would really recommend tying her to an innertube or in such a way that the rope gives slowly when she pulls on it and see if that cures her.
She has figured out she can break out of being tied so avoid any hardware that isn't strong enough to hold her weight.
I would not recommend a rope halter. It won't break, but it also could give her permanent nerve damage to the poll or cut through her skin if he pulls hard enough.
And I am not a fan of John Lyons either... he once dismissed animal psychics saying he wouldn't want to know what his animals are saying and while I respect his right to believe anything he wants to, I was disgusted by his dictator statement... but a few of his training methods are so easy to implement it is almost ridiculous.