I would have ended Ripley's presence in the franchise arc with the end of
Aliens. It was the natural and fitting place to say goodbye to her character.
Newt, on the other hand, had great potential in
Alien 3. Just as Ripley had unfinished business at the end of
Alien '79 dealing with survivor guilt from her Nostromo experience (and also surviving her daughter); Newt, in film 3, would have unresolved issues following the death of her family at Hadley's Hope. Maybe, as an adult, she could have ended up on Fiorina instead of Ripley.
Hmmmm...
So Newt Jorden, mid-20s, fuelled by a search for justice, signs up with military intelligence to learn more about Weyland-Yutani's shady dealings. Ripley has retired, having raised Newt, and Hicks is nowhere to be seen. Newt receives a message from an anonymous informant about some suspicious activity in an off-world penitentiary being run by W-Y. So she flies there, crash lands (W-Y sabotage her ship before she leaves), gets rescued by the inmates, and discovers that the prison is a front to hide dangerous xeno experiments taking place in the basement (using the occasional inmate as research fodder). Newt organises a prison rebellion and eludes a stalking xeno before escaping in a visiting W-Y science vessel that shows up to deliver "product" to the basement laboratory. The vessel is the Auriga.
And on to the next movie...
Onboard the Auriga, Newt learns that years ago during the events of Hadley's Hope, Burke was beaten to Acheron by a secretive W-Y science team that managed to bag a few face-hugged colonists after they were hospitalised. One of them was Timmy Jorden. The Auriga scientists had cloned him to recover their first xeno. He is kind of Newt's brother (having his memories), but kind of isn't (exhibiting odd xeno behaviour). Caught while trying to free Timmy, the two are rescued by a W-Y lab assistant - in reality an undercover saboteur named Call, secretly embedded by a governmental special ops unit tasked with taking down W-Y. Newt and Timmy band together with Call to set a timed charge in the Auriga's fuel core. Call says a mercenary supply ship that is due to dock in a few hours is actually an extraction team organised by her special ops unit. If they can make the rendezvous in time, they can escape the explosion. Timmy uses his "xeno-senses" as they fight their way through a xeno breakout but he dies in the battle. Newt and Call make it to the extraction point as the rescue ship docks. The pilot is Hicks. Not there by chance, he's been undercover in the special ops unit for the past 15 years and he was the informant that gave Newt the initial lead about WY's Fiorina prison experiments. He dies in a battle fending off W-Y soldiers as Newt and Call escape in the rescue ship just as the Auriga explodes.
And on to the next movie...
The special ops unit has been disavowed and Newt and Call are on their own, still battling to bring down W-Y.
Rebecca "Newt" Jorden
Tee hee
TC