You should NOT I ..... repeat NOT..... trim that sole over the toe without knowing if she is foundered and knowing how to tell if it is excess dead sole or actually BULGING sole due to a rotated coffin bone !!!!!
If she is foundered and the coffin bone is rotated, the edge of the bone could be VERY CLOSE to the ground and that "lump" of sole could be the only thing covering it.
A FAR better thing to try while waiting for the farrier is to cut some dense foam padding top fit inside the bottom of the foot and fill the bottom of the foot with it, and duct tape it on. Gardner's foam kneeling pads work, or constriction grade firm styrofoam.