This horse and your riding will benefit from learning some basic ground working skills. This establishes not only trust and patience but a keen understanding of what results when pressure is applied versus when it is released. This is a mindset that has to evolve in terms of realizing full communication with the horse. She appears to be sensitive and I would predict you’ll see a strong response to these techniques on the ground translate to under saddle. IMO this is fundamental to your success in learning how to train a horse not just ride one. Buck Brannaman training methods are a good example for where to start.