Going from the 90th century to the 30th seems like a demotion, somehow.

Still, she fought her way into the main continuity, so that's something; even if Legion continuity has the structural integrity of a soggy ham sandwich...from 1996, the Power of Shazam Annual #1, "True Believers" Written by Jerry Ordway, pencils by Mike Manley, inks by John Nyberg.

This was another of the "Legends of the Dead Earth" annuals, wherein earth was long since gone and forgotten, but the legends of its heroes lived on, in different fashions. On a world called Binderaan, "science is god," and perhaps not a forgiving one. In a robbery gone bad, "aberrant" Dash Noir seemingly vaporizes young CeCe Beck with a "magick" weapon, then Beck's parents are killed by a collapsing police robot. Noir is arrested and taken to the hospital to be put back on the government's "daily vitamins," which are almost certainly something more sinister. Beck, however, ends up in a mysterious junkyard, apparently where items zapped by the magick weapon go, then is chased by a local animal, an omuta. She then falls through a rock trying to escape, not hearing the omuta explain he was just looking for someone new to talk to...

Within the rock, Beck finds the familiar Seven Deadly Enemies of Man statues, then a cobweb-covered body. She's surprised to find the "body" alive, although he has a little trouble getting information out of her. Meanwhile, the police have got the location of the aberrants' hideout out of Noir's mind and raid it, intending to gas everyone unconscious: "These families are misguided, not lost causes!" Still, the aberrants set their magick dust weapon to activate if disturbed, sending them and the police to the rock--the Rock of Eternity! For protection, the old wizard tells Beck to say his name, Captain Marvel, and she transforms into Thunder!

Thunder and Cap--the Wizard, as he quickly warns her, don't say his name--sort everyone out. While the police, working for the Science Council, see the aberrants as non-conformist unproductives and the omuta as "freed," they didn't put any effort into integrating their former workers into a new, more technology based society. Not that the aberrants were blameless, though: the two that were already at the Rock, Old Crow and Chatty, recognize their old pals that tested the magick dust weapon on them! The police inspector, Javert, explains they had also been part of the robbery that killed two people, although they try to pin that on Noir. Intent on returning to deal with him, Thunder asks the Wizard to get them all back to Binderaan; while Noir, having played along with the police to rebuild a magick weapon, escapes to the Rock and meets not the Wizard, but the Three Faces of Evil. Who offer him a job...(The Three Faces were a recent addition to the Shazam stories; why them instead of the Seven Deadly Sins? Unless because it's four less to draw.)

Due to time flow problems, by the time Thunder gets to her home, it had already been given by the government to another family. Thunder is mad, and the sudden arrival of Javert doesn't do much to improve her mood, but he knows who she is and needs her help. Noir had returned as a Black Adam-type, and tore up the Science Council for not acknowledging magick. After the usual fight, Thunder manages to imprison him within the Rock of Eternity; then advises Old Crow and Chatty, they need to return and help their people out. CeCe is adopted by a new family, and keeps her powers to help her world. Which she actually might have! Unlike a lot of the characters from Legends of the Dead Earth, Thunder would appear again; first in Power of Shazam #44, but I'm not sure she ended up there! She would join the post-Zero Hour (first reboot) Legion in Legion of Super-Heroes #110; although I don't think she had a ton of appearances: the book was going to go in a darker direction, and that series ended at #125.