Horse becoming too herd oriented, how to re-gain trust?

Seems she is not well broke and lacks foundation training. The horse's reaction to being in a socialized atmosphere is normal. If she trusts you, she will be willing to come to you and be with you without being stressed. I can walk out into my pasture and either one of my horses that I ask to come to me will leave their buddies and walk over. Many times, they will seek me out just when I am present. We have a relationship that is solid and sound and can never be interrupted. They have ultimate trust in me and are comfortable in any situation. Just a matter of trust and the loss of fear. Get a foundation and it is fixed forever, not matter what happens.