she was.
the difficult thing for cameron was somehow reversing the personality of ripley based on the 1st movie.
in the 1st movie she was capable from the getgo.
so the way he reversed her from strong and capable to useless n weak was by terrorizing the character with dibilitating nightmares.
she couldnt cope. then she decides to face her fear, perhaps the way to end the nightmares, was by going with the marines to exterminate em all.
point is, he reversed her character, to build the hero character arc.