Carolyn Jillian is a character in DEXTER. She is referred to as a "powerful woman", likely being something of a prosecutor, a businesswoman or a person of political power. When Vanessa Gayle ends up killing herself, Dexter Morgan relates her death to that of Carolyn and Meghan Dowd, ultimately revealing that Dr. Emmett Meridian manipulated all three women to kill themselves by depressing them with overprescribed medication and then his own words to urge them into shooting themselves. Dexter discovers video footage of the three women, with each girl expressing their need for the medication and then Meridian goes on to describe death by suicide with a gun. He is eventually caught and killed by Dexter, thus avenging the three.
Humorously, Dexer refers to the three as the "Suicide Sisters".