That’s a huge prolapse gently feel to make sure there isn’t an egg in there. Be sure to have clean hands. I wouldn’t put her in hot water Luke warm but not hot. This needs to be lubed up and try to gently get it back inside but make sure there isn’t an egg. Actually a vet might be best then they can put a stitch to keep it inside. You don’t want it to stay out and dry out. Keep her inside so it doesn’t get dirty. Soft towels would be best nothing that will stick to this prolapse.