She chirps constantly, but not screeching as if in pain. I don't know if I should cull her or continue to wait and see if she will be able to get around. Thoughts?
Given what you have already tried, I am guessing that can not be fixed (although of course I could be wrong).
I don't think she'll be able to run, scratch, or roost normally. I would also expect her to have sores or other issues from using the foot strangely.
Personally, I prefer to cull chickens with special needs. I'm not willing to commit the time for monitoring and tending unusual conditions, but I am not willing to let an animal be neglected and suffer, so I cull them.
I know that some people have chickens with various special needs, and the chickens appear to live happy lives with some accommodations, which those owners are willing to provide.
Obviously, the "right" answer is different for different people