Kalypso is the sister of Helen Mirren’s Hespera, and they both share the same father, Atlas, one of the legendary figures who Billy Batson draws his incredible power from, specifically stamina.
Like Hespera, Kalypso doesn’t have a specific counterpart in the DC Comics canon.
It’s been officially announced that Lucy Liu will take part in Shazam!
Fury of the Gods as Kalypso, one of the eponymous deities.