Cynthia was one of the hosts of a horror comic DC published in the 70s called "The Witching Hour". There were two others, a fat witch named Mildred and an old hag named Mordred. Cynthia would usually tell stories that were more modern compared to her sisters.
In "The Sandman", Neil Gaiman brought them back but transformed them into "The Three In One". The Triple Goddess concept. The Fates. The Furies. Maiden, Mother, and Crone.