Drive her on long reins around the place. Get two lunge ropes and clip them to her bit, or sides of noseband on the hackamore. Put both ropes through the stirrups and, with both long reins in hand, stand far back enough so she won't reach you if she lashes out. When she spooks at something, swish the opposite side of the rope so it taps her on the butt and encourages her to move on past it. To get her to move in the first place, swish the ropes with a flick of your hand and talk to her. This should stop her spooking at a few things! Also, only do this in walk. Not trot!