Hooflex is made for horses to soften their hooves and prevent cracking and chipping. It's safe for goats too. Just put it on the outside and rub it in the crack really well, probably once daily. But don't put it on the inside of the hoof. The hooflex comes in two different forms...a liquid to paint on and then a grease like...bag balm. Get the stuff in the plastic tub...the grease stuff...it will stay on longer.
It sounds like her hooves are dry, helping prevent the healing. If that's not the case then the hooflex probably wouldn't do much. But if you can get a pic later that'd be great!