First you need to treat for shock. Get her into a warm, quiet, low light place and do the best you can to gently check her over for any other wounds or injuries. She needs to stay warm and hydrated. Putting electrolites in the water can help with the shock. If she has any wounds that are visible clean them the best you can, but be aware that handling her too much at this point can make the shock worse. It's a judgement call on what really needs to be done immediately. If the wounds are minor, then let her recover a while before messing with them. You can use sterile saline, chlorhexadine, or veterycin spray to clean any wounds and then a plain antibiotic ointment on them. If you post pictures of specific wounds it will help getting more specific advice on treating them.
If your other birds are 'gone', and you didn't mean killed, they may be hiding. Check your coop at dusk to see if they return.
