Trish, I would suggest training the horse to target an object (like a milk jug) when your daughter approaches the pasture. This will accomplish a few things for you:
The horse cannot possibly lift her front feet and bare her teeth if her nose is touching the target.
The relationship between your daughter and horse will start to changeinstead of a battle, the horse will learn that your daughter is associated with good things.
It will make bringing the horse in from the pasture much easier.
So, how to do it? I would start while the horse is in her stallshe first needs to learn to associate a sound with the delivery of a tasty treat. A whistle through your teeth can be a great option, or a crisp, clear "yes." Make the whistle, then give the treat (small pieces of carrot work well). After a few pairings, your horse will likely look to your hand when she hears the whistle. Now, present the milk jug so that it is close to her nose. When she reaches to sniff it, whistle and treat.
Once she is placing her nose on the jug, we will give it another sound cue"target" works wellso the sequence will be to say "target" as you present the jug. She touches the jug, you whistle and then give a treat. Now, increase the length of time she has to keep her nose on the target. Finally, hang the target in different places in the stall, give the cue, wait while she holds on target, then whistle and treat.
Now it is time to bring the behavior to the pasture, where the behavior we want to eliminate is occurring. Start by staying outside the pasture, but hang the jug to a fence post near the gate. Ignore any teeth baring, etc.simply cue and reward for target. When she is consistent, keep her on target while you enter the pasture. Reward her for staying on target while you enter. This should eliminate the behavior fairly quickly, and at the same time, help to change the dynamic between human and horse.
Best of luck!