K'hym lived with her father, mother, sister and grandfather on Mars. One day, on K'hym's father's birthday, her grandfather came home early from worship to surprise him. J'onn walked in, appropriately surprised, and impressed that K'hym and T'ania kept a secret. Eventually, however, her family was attacked by the White Martians, a subterranean race who then wiped out nearly all of their people in a Martian holocaust. K'hym was killed alongside her mother and sister leaving only her father and grandfather alive.
- "Strange Visitor From Another Planet" (flashback)
- "Survivors" (mentioned)
- "The Darkest Place" (hallucination)
- "We Can Be Heroes" (indirectly mentioned)
- "Far From the Tree" (memory)
Behind the scenes
- In the comics, K'hym J'onzz is the only daughter of J'onn J'onzz, who was killed along with her mother in the plague that destroyed most of the Martian population.