Talk to her a lot when you are riding
Give her something to focus on. Transitions, serpentines, etc. my mare is green as well. Try to always push her forward and don't take from her. Always reward her, even if it's a menial task
Lots of circles, baby leg yields, transitions. This keeps her mind on the work and not on what is scary. This will build her confidence in her job. Also try riding with an older calm horse. If she seems them working well and calm, then she might catch on to the game. Hope this helps!
Horses can tell if you are nervous or not confident, they can sense it. You might also want to try some ground work in a round pen on a lead getting the horse to respond to your voice commands. She might also need to free lounge for a few minutes. It just takes time to build that relationship with your horse.