Thanks for the info about the Vaseline, you may have kept someone else from killing their bird.
We went through the first egg prolapse yesterday also. Buffy's butt did not look as bad as your bird, we had no bleeding. I soaked her in warm water, cleaned her up and made an incision to remove the egg, then slathered her with neosporin and pushed the membrane back inside. Today she is walking around the yard acting fine although her butt is matted, wet and covered with crap. I will catcher when I can and give her another bath and lube her vent with more neosporin unless I get better advise here soon. Thanks again for sharing what your vet told you.