Welcome To BYC
I'm sorry to hear about your chicken.
When did the injury happen?
I'd clean the wound with saline or something like Chlorhexidine or Betadine. Try trimming some of the feathers away from the wound so you can see it a little better. Once cleaned, apply triple antibiotic ointment to the wound.
If this just happened within the last 24-48hrs or so, she may just be really sore and over the course of a few days she'll start putting some weight back on the leg (cautiously).
It's possible she may have suffered some nerve damage or something else and recovery may be long or she may never regain the use of her leg, it can be hard to know immediately. Time will tell more.
Wrapping the leg. Normally you leave a wound unwrapped. I'd be inclined to leave it unwrapped at this point. You can place her in Sling to help keep her more upright and take the weight off her legs. Being in a sling, the bird does need monitored and taken out of the sling for periods of time as well. Link below give more info/photos of various slings/chairs.
Is she eating/drinking? Giving a little sugar water or electrolytes can help move them through shock. See that she's eating.
https://www.backyardchickens.com/threads/versions-of-chick-chairs-please.1166308/