I've had button quail scalp each other or try to kill each other, to the point where the entire scalp was peeled off of the skull and blood was spattered all over the cage.
Quail are very tough. They are evolved to withstand rough treatment by the males when they breed. My coturnix roos fling the hens around by their head and neck feathers, and the hens only lose feathers. My button quail all healed up fine. I used a bit of Polysporin on the scalped areas and this helped it heal faster. Blu-Kote is another product you can use to prevent wound infections and speed healing.
It's normal for a quail to be less active after it's been scalped or wounded. They may stand in a corner in a hunched over position with the feathers fluffed, and they'll go off of their feed. This only lasts a day or two after they are injured, then they gradually start to perk up and eat again. I'm guessing it's a shock reaction to being in pain, as well as a way to avoid predators when they're vulnerable.
Personally I wouldn't leave a wounded quail with other birds, especially males, in case they pick on her. I'd give her a few days until she's acting normally, then try putting her back in with the others.