From Alien Woman, the Making of Lieutenant Ripley

In the final scenes of alien, ripley meets not just an alien creature, but a dark physical and psychological mirror of herself. The film ultimately pits the body against her own shadow self. In a world where men can be sub ted to the monstrous feminine, becoming pregnant and give birth to monsters, women can become the heroes and soul survivors. And yes, that's when ripley, like seart confuter man, a dream.