This is going to upset some people but I would get a AFA (American Farrier Association) certified farrier out to look at her and put shoes on her. The problem with horseeshoers and barefoot trimmers in this country is that all you need is a business card a a box full of tools to start a business. You may have a very good trimmer or you may not. By your own admission you don't know much about it. I doubt that the hoof grows out with a crack, it probably is weak and cracks from excessive pressure. Even if you want to go barefoot in the future consider getting a certified farrier out to look at that foot to see what can be done. The AFA has a pretty extensive testing process so the people that are certified have a pretty good grasp of hoof care.
There's nothing like the Rockies in the springtime... Nothing like the freedom in the air... And there ain't nothing better than draggin calves to the fire and there's nothing like the smell of burning hair. -Brenn Hill