Six episodes into “Superman & Lois,” we’ve gotten a lot of clarity on how “Crisis on Infinite Earths” changed things for the Man of Steel. And though the massive event gave him two sons instead of one, it didn’t change anything else about his family — so why on Earth (or rather, Earth-Prime) has Supergirl not been mentioned at all yet?
Technically, “Superman & Lois” is a “Supergirl” spin-off show. Clark Kent/Superman made his debut in the Arrowverse in “The Adventures of Supergirl,” the first episode of the second season of “Supergirl.” He stuck around for a couple of episodes, then primarily appeared in network crossover events after that.