Remember, the average horse is six to ten times heavier than a human and you have to maintain discipline for the safety of yourself and others in your yard. A pat and words of praise will do. The final resort is to keep a muzzle on her but that is only prevention not a cure. There is no substitute for firm discipline from all concerned with horses. Hope this helps and please send me an email to let me know how you get on.
Feedback is always interesting and useful.