That looks just fine. The frog can shed a couple times a year. It looks like your farrier isn't touching the frog and that's just fine. It's a natural process. The only time we help it out is if a large flap occurs. Fungus and bacteria can get under a flap, which can become thrush.
What I would be keeping an eye on is picture number four. There looks to be some seperation starting around the white line. When was she last trimmed?