Oh, so you are tlaking about working with her on the ground.?
She may not be understanding your command. You may need to just keep tapping until you get the correct response, so if she backs up you don't stop tapping, you keep it up, watching and waiting for the correct response. Even if you must back up and follow her.
I would like to suggest you watch a short funny little video I made. I am NO PRO. Just a total amature schmuck of a rider, but I can share this small thing.
Look at how I use the leadline to help "suggest" to the horse the direction I want them to move. And remember that the horse cannot lift and move a foot over if THAt foot is weighted. Must have weight on the other foot in order to lift the one you want and move it. How to get your horse away from you so you can begin lunging him around a circle