All these ideas of Riley doing a scan and use the sulacos systems: I doubt she knew how all those systems work or how to do a scan, she isnt military but civilian and advicor on the mission and I highly doubt all the tech onboard are opened for anyone to use, minimum codes for the higher operations would been needed and then one also need to know what one is doing and what commands to press etc. Hell some people today struggles when using an iphone vs samsung in the menu....
And bishop was probably deactivated or barely working after the damage and hicks is out too so have a feeling ripley just focused on doing visual checks and then making everyone ready for the home trip and after all that they went through, they might not be thinking 100% straight either.
But thats my own theory on it