Cain and Abel were each born with twin sisters; Cain's twin was Aclima and Abel's twin was Jumella. The brothers were intended to marry each others' twins though, being Abel's twin, Jumella was fat and regarded as undesirable by Cain. Cain instead wished to marry his own sister, and it is said that the real reason he killed Abel was to free up Aclima for himself, though she would ultimately run away from her family.

Now left with only the repulsive Jumella to marry and reproduce with, Cain chose instead to lock her away in the attic of The House of Mystery and claim that she ran away with Aclima.

Jumella spent thousands upon thousands of years wasting away in the attic, her only company being the sentient House of Mystery itself which shared her hatred of Cain. It was not until her youngest brother Seth came to the House of Mystery trying to solve some family mysteries that she was freed from her captivity. Upon being released, she attacked Gregory the Gargoyle; Furious that he'd gotten fat eating food off the table while she had to survive off bugs in the attic. Ultimately Cain forces Jumella back into the attic. (The Dreaming #8)

When the House of Mystery became so sick of its miserable existence that it burned itself down, Jumella was was rescued from the burning building and finally freed from her prison. She then took up residence in Eve's cave. (The Dreaming #28)