Whenever I ride my fjord even remotely close to the pasture, she gives me one hell of a time trying to keep in control. First I'll try to ease her away, then I'm forced to get a little rougher. Finally, I can't get any harder on her without hurting her, so I have to dismount and walk her for about half an hour down the trail until every site, scent, or sound of that pasture has disapeered. It's really bothersome. How to I make her stop?