Hello oletymer, I also have a pullet who got frost bite on her toes. They were shriveled as in your pictures, but they ended up falling off on her left foot, which was worse, but on her right they have not fallen off but are still shriveled. She now has just a stump for her left foot, but she gets around fine, (though with a limp understandably), and she has even been jumping up to the second level of roosts at night.
It looks to me like your pullet's toes might or might not fall off. I would keep an eye out for any infection that could occur. I did not have a problem with that, but from reading other posts, it is possible, and it would be good to keep an eye on her anyway.
I hope this is helpful.
Blessings, Hischick