Air circulation is the best preventative. Once its there it needs to be addressed, treated and the hooves kept as clean and dry as possible.
I'm sure she's just tender from walking on sole she hasn't walked on in awhile.
Its like if you wear your nails long for awhile then cut them off. Your finger tips will be tender for awhile.
She probably will need to be on a 4-6 week rotation with the farrier for awhile.