I still have two options.
1.
There is no egg on SulaŃo. Just an unexpected accident. People die, Ripley survive. She received severe stress and depression, leading to hallucinations and psychosis. She began to slash prisoners and staff. Maybe she imagined herself an Alien, or as if thinking that the Alien was killing everyone, and she was observing from the side. Perhaps Golik helped her. He saw a kindred spirit, so to speak.
This is a very dark and very fincherish story. But I have a light.
2.
Cryo-nightmare. Well, you know. Just a bad dream, that Ripley had when she flew back to Earth along with Hicks and Newt. I use this option not only to exclude Alien 3 and AR from continuity. I also use this option to explain all the illogical, mystical inconsistencies and plot holes.