start by teaching her to lead by driving her. I mean you can lead a horse from in front, and you can "lead" a horse from the side or from behind, you just have to use more driving than pulling. ( I dont' mean to say that you pull her when you lead, but the hrose is following the feel of the rope on her halter) in leading from the side you give her more line , you stand off to her side and you put a little pressure with a stick or whip, pointing it at her hip area and kind of inviting her with the leading hand to move forward. you work on leading her around her pasture by kind of sending her around, and it's fun to do it where you put things around the pasture, here and there, and put a treat on them. Then, send her ahead of you toward the barrel or whatever thing is there, and let her sniff it until she finds the treat.
it's always good to know how to "send " your hrose. you can use it to send them onto the trailer, through a narrow spot, a gate or into a stall ahead of you or whatever.
once you can send them ahead of you, you can send them ahead of you and you stay put, in the middle of a circle, and they learn to continute forward, as long as you keep asking them to.