Oh, I see now. The other photos just showed the top and the toes, but I see that it is loosening at the footpad. If she's going to lose that, it's going to take a while, but it sounds like she's hanging in there and not letting this stop her.
I think you are doing a good job taking care of her.
You're getting excellent advice from @Allsfairinloveandbugs she has experience this first hand and you can't get any better than that, imho.
As mentioned, an antibiotic may be necessary at some point, but if the healing is taking place...
Here's the article @Allsfairinloveandbugs wrote, it's very detailed and packed with information about care.
https://www.backyardchickens.com/articles/frostbite-what-to-know-about-injury-care-and-recovery.78168/
To me, it looks like she will probably lose the whole foot up to the point where...