I honestly don't know if a making collar like you use on a dog would work or not. It may not stay on and she might freak out:D
For antibiotics, if you can get by without using them, that would be best. If you start to see signs of infection or the wounds have an odor, then usually you can...
Hi @I'm a Country Girl :frow Welcome To BYC
The green is most likely bruising.
Keep an eye on it, hopefully the discoloration will disappear in a couple of days.
I don't normally recommend covering a wound, but if she is picking heavily at the wing, then you may want to consider covering it...