I don't see anything wrong with her skin.
I would stop the baths.
Weight loss doesn't happen overnight, so weight gain will be gradual as well. I'd focus on her eating her normal feed, if she's eating that well, then she'll get to where she needs to be.
Sometimes it's hard to go by weight to know the condition of a bird. You don't want fat and overweight hens. Fat on hens usually deposits around the organs (heart/liver) and in the abdomen. Fat can lead to fatty liver disease, fat in the abdomen can make it harder for hens to lay eggs and they can be more prone to prolapse.
You want to feel her keel bone. Here's a score chart.
http://www.poultrydvm.com/featured-infographic/chicken-body-condition-score-chart