Id have a chiropractor look and see if she out anywhere that might cause that lead to be painful. Or perhaps find someone who can help you get her over this problem
She is able to do the left lead she will pick up the right and do a lead change to left she has suffered frome epm and is doing better but how do I calm her down in general she tends to be really anxious
Take your time your horse may not know what you are asking or be pyisical unable to do this have him checked make sure there is no underlying problem and then slow everything down ask for trot and even if he speeds up reward the try then ask again. Then do the same trot to canter.