Just to give everyone an update, I was gone for a few days this weekend. Before I left, I had let her soak a few times and also cleaned and sprayed the area with an antibacterial spray.
Today I noticed that the unidentifiable black mass on her vent was gone. There wasn’t any blood or anything and I saw her regularly preening that area. She’s been eating and active and even pooping. Not sure she’s 100% ok or not but it’s look better than I thought. I’ll continue to monitor her and see how it all goes