Is the vent extended completely ? If it is it sounds like prolapse. Birds can recover if helped soon enough. As was mentioned above me here set her in some warm water, clean all you can and wipe away best you can. If you are skiddish or shy about things, don,t be.
You can use your clean hands or if necessary rubber gloves and ever so gently try very slowly to help reinsert and see if she tries to do the same. If you can see or feel that she is trying to help you, continue to do it some more . If she does not react just give her a while in a warm place free of drafts for a while and keep an eye on her. I have had hens survive days with prolapse and they eventually got the strength back to retract their prolapse situation. Some birds don,t make it but keep the chin up.
If I am right and it is prolapse I try to help them out and help them lubricate the prolapse with mineral oil... Very helpful for me. Best of luck..hope she does well... Steve(BunkyB)