Welcome to BYC. It sounds like she has a vent prolapse and fly strike from maggot infestation. You need to get her into a warm bath with one of the following added to water: weak betadine, hibiclens (clhorhexidene,) epsom salts, table salt, or dish soap. Soak her and try to get all of the maggots, even using tweezers, and after you dry her off, apply plain antibiotic ointment such as bacitracin. A permethrin spray or ointment such as SWAT can be used to kill any remaining maggots. The bath should be repeated as much as need to get all maggots. I've never dealt with both flystrike and a prolapse. The vent should be pushed back inside if possible, honey or hemorrhoid cream applied to reduce swelling, but I would get the maggot issue resolved. You may need to cull her if she seems too far gone or suffering. Please post pictures if possible.
