Obviously I realize that. Regardless, why does she let Parker go off alone? She was in command and she ordered Ash to go with him. She should have said "Hey idiot, giant alien just killed two of our crewmen, one of them the captain -- you're not going alone." She certainly didn't seem to have any trouble taking control, so why did she let that slide? Ash just walks off like he's going off to his bunk or something, but no big deal? Hell, why didn't she tell the other woman to go with them too? Why did she let her stay in the room alone?
That's just one scene too, the movie is filled with shit like that. Again, why was there only one escape pod on that giant ship, and why didn't it have enough stasis beds for -- at a minimum -- the crew it started off with? And if Ripley is so smart, why the fuck did she leave her position to go and get the cat when she heard it meow? There were 3 fucking crewmen left at that point and she had already (stupidly) sent the other two off and was by herself. But damn, the cat! Gotta get that cat!
Watch the movie again, and do so with have of the scrutiny you're levying against Prometheus. Your eyes will roll. Face it, we were younger and dumber when we saw the first Alien so we let the bullshit slide. It was just as silly as Prometheus. Justifying it by saying they weren't scientists is silly. Have you ever met an actual scientist? Most are extremely narrow-minded and are really good at one particular thing, but should never be trusted in a practical situation. Regardless it's a silly argument; obviously there were weapons on the Nostromo, so as soon as they entered SJ's ship and realized what it was (which was clearly obvious as soon as they set foot in it, if not earlier) they should have gone back and gotten them, bottom line. Certainly, proto-chestbuster host shouldn't have been docking around with the egg sack. I guess he gets a pass though since he wasn't a scientist. LOL