Keep up the warm water bath. Do not attempt to probe the vent. You can end up causing a prolapse and killing the pullet. Give her some olive oil orally with a needless syringe, lots of grapes or even raisins to soften her stools. If you have any non-stick cooking spray, like PAM, spray it on the vent every time you clean it. It will prevent any feces from sticking and moisturize and protect the skin. Her problem is in the intestinal tract. You can add some apple juice concentrate to her water or even a bit of sugar to give her energy if she isn't eating. If she is eating and you have some aloe vera, mix a tablespoon to a half cup of chick mash. Even water in the feed to moisten it is good. If you have some Nutri Drench give her 0.5 mL syringe for boost. She should be separated from the other pullets by now. Do what you can for it, then be at peace with the outcome. Chickens are so tuff, and at the same time so fragile.
Good luck.
Good luck.