I don't know what she did but I will try the baby asprin thank youI'm sorry no one has responded. How did she hurt her foot, do you know? I'm not sure how to help, but I would suggest a baby aspirin or a low dose aspirin dissolved in water for pain.
Hoping someone else will chime in...
Thank you she is limping but she isn't pecking at itAnytime a chicken is sick they can benefit from extra heat - time in a warm space and/or with a heating pad could be good.
Have you throughly examined the foot for any scabs, punctures, etc... Don't forget between the toes.
Is her swollen foot feel hot compared to her healthy foot? It looks like there is some reddening which may indicate infection.
As a first step (other then moving her into a warm space), I would suggest soaking her foot in an epsom salt bath - this should help to relieve some of the inflammation and may make it easier to ID the source of the problem.
I'll call some more experienced chicken peps to see if they can help you narrow down the cause of your hen's foot trouble. Ideas @Wyorp Rock, @oldhenlikesdogs, @azygous , @Eggcessive, @aart,