Stop riding until the soreness is gone. It is most likely from thrush and you will need to clean and tend to her hooves daily not once a week. They also need to have a proper trim. Where are you located? Someone might be able to give you recommendations on good farriers.
I do clean her hooves (pick and brush) everyday. I only wash them out once a week. I can do it every day if need be. I live in Orange County, NY. Will be picking up some sort of thrush colution today, but am looking for some recommendations.
Look up some of the threads here on thrush. The best stuff to use is for cows called Tomorrow or Today. One works better but I can't remember which one. You have to scrub out the feet with dawn dish soap works best, let dry then put that stuff as far into the crack as you can and stuff with cotton to hold it in.