You need to treat the leg with an antibacterial spray or lotion then wrap it with a clean cloth. Change the cloth out every day and add more antibacterial to the leg. Take her out of the coop and bring her inside or to a garage where you can watch her closely and where she is very comfortable. You'll just have to take it one day at a time and think about what you'll do with her after she is healed. Do you have any idea what could have done this? I think it would be good if you took the rest of the flock out of the coop and put them somewhere safe until you catch whatever did this to your girl to prevent this from happening again or worse. Feel free to ask more questions and good luck!
Apply a triple antibiotic ointment without pain relief, or an antibiotic spray to the wound. Bandage it, gauze and vet wrap may work. Repeat those steps daily, and switch to an all flock or grower feed if you weren’t feeding them that already.
Do you know what could’ve caused it? Did you find the leg? Can you post a picture of the wound, and the leg if you found it? What does your coop look like? Were there any obvious signs of an intruder?
Thank you , I did what you said and cleaned the wound and I did remove the other chicks. not sure what I will do with the hurt chicken, but I definitely didn't want to put her down, I do have her in a little kennel with some food and water with another little chick that seems to stay with her and helps her along. She does eat and drink , Just wait and see.