Decades have passed, many things have changed, some things haven't and everybody she knew including her daughter has died of old age.
With her report of events dismissed and being made a scapegoat for the financial loss associated with the Nostromo, Ripley ends up doing low status work to scrape a meagre living. The planet where she encountered the Xenomorph is now a small colony and nobody has ever encountered anything like it there.
That is until one day her Company case worker Carter Burke (Paul Reiser) knocks on her door asking if she will join a mission there as a consultant. It seems they've lost contact with the colony...
No good will come of this.
More is usually not better but Aliens dodges this problem by not being a straight sequel.
Survival horror and themes of violation are replaced with a post-Vietnam war movie (the "good guys" lose mostly through overconfidence/arrogance, but do so individually heroically) and Ripley embracing adoptive motherhood of Newt through forceful action. It has callbacks to the first movie and inversions.
Some of the dialogue from the supporting cast clunks a little early on and Newt screams too much but other bits of the dialogue are so oft-quoted it's embedded itself in popular culture. "Nuke from orbit" etc.
The action scenes are as good as the 80s got and things like the animatronic Alien Queen have a proper sense of scale and menace. Shots like when the cargo bay door opens to a backlit Ripley in the power loader are iconic.
It's oft credited as catalysing the rise of female drama/action heroes in big movies and I'm not well read enough to make much of an analysis but the way in which Ripley actively complements the macho Marines rather than just being a female macho Marine (per Vasquez) is very very unusual role for a 1980s blockbuster. It's also a clear step forward from her similar role in Alien.
Still an absolute classic of blockbuster cinema and one of my favourite films 10/10 but you've all seen it anyway.