Jennie, does she have any open wounds? If she does, you should probably put her on a course of antibiotics so that any infection is dealt with. I had a hen that injured her leg someone several months ago; I separated her into a smallish dog crate so she couldn't exacerbate the injury. She ended up staying in that crate for 8 weeks. The first 4, I took her out only to change the bedding. After that, I allowed her into a small chicken run (4' x 8') to stretch her wings & see how she was doing . She was still limping, but I watched her closely to make sure she wasn't running around. Another 8 full weeks of her staying in that dog crate and getting about an hour a day out in the small run, and then I began putting her in the run for half a day (for a week), now all day - she's been alone, all day, in this small run, now for a few weeks and is doing quite well. I'll wait another week just to be sure, but my hen is hopping in & out of the nestbox & up to the roost, so I think she's almost ready to go back to general population. I'm quite sure she had a broken bone, and those take weeks to heal. The slower, the better, in my opinion.
Your hen won't lay if she is stressed, but I wouldn't worry about that now. If she lays, she lays. If not, don't worry about it. You need to get her healed up first & foremost.
I wouldn't do anything to stress her (like give a bath) at all. She needs to remain quiet.