Ripley is found 57 years after the events on the Nostromo. Plagued by terrible nightmares, she's forced to attend a court hearing about her last mission out. Without a single shred of evidence, they think her story is absurd. Her license is suspended, and she's forced to undergo a six-month period of psychometric probation.
After contact is lost with LV-426, Ripley is asked to accompany a combat unit there as an advisor. Only after Burke assures her they won't study or bring back specimens does she agree to go. But she knew she didn't have a choice. She had to go back out there.
Ripley's license is reinstated, and she's given the rank of Lieutenant. Immediately, she has a natural attraction to Cpl. Hicks, a natural leader among the soldiers, and she befriends a tough little girl named Newt, becoming a kind of surrogate mother to her.
She figures out the marines can't use their weapons in the Atmosphere Processor, because they'll trigger a thermonuclear explosion. Once the marines find the colonists and kill a Chestburster, she warns Gorman to pull back, but he ignores her.
Against Gorman's objections, she drives the APC into the Atmosphere Processor to save the marines. She doesn't show any fear even when an Alien breaks in through the vehicle's window and nearly kills her. Afterwards, she figures out a new plan. "I say we take off and nuke the entire site from orbit. It's the only way to be sure." Hicks agrees.
Ripley always makes sound decisions. As Hicks confirms, she can take of herself. He shows her how to use the Pulse Rifle and its grenade launcher. When he gives her a locator device, she wisely passes it onto Newt. Because of this, Ripley is able to save Newt later and keep her promise to protect her. Ripley is a brave warrior with strong instincts.