First, I would rather have one that is stubborn to walk than one that wants to duck and drag!
I would NEVER tie to a tractor, or any mechanical device. If she isn't running from you, or trying to get away, she just needs help moving forward. It is OK if your show heifer does not walk in the ring, there are always ring men there to help move her along. ALSO, there are typically several animals in a show class, and she would likely do better to follow another heifer that is walking in front of her. Having someone with you when you are walking is a must, to tail here or do what it takes to get her moving forward. A good dog is helpful too! When the kids are working hair over the summer, they always have my Corgi with them. The heifers HATE walking to the wash rack for the daily rinse, so the kids just call the dog to help, who lightly nips at the heifers back heels to get them moving.
Last, have you heard of the cable halter? You can get them from Sullivans, we made a bunch of our own (we break over 30 calves each fall - some just need it). It is a life saver for us on cattle that like to dip the head to pull away, or heifers that just do not want to walk (pull release with this halter). Here is a link to the
Cable halter
Hope this helps! We have been breaking and showing cattle since 07, so we have done a bunch.