In MOMMY DEAD AND DEAREST, provocative documentarian Erin Lee Carr (HBO’s “Thought Crimes: The Case of the Cannibal Cop”) again explores a crime in the age of social media. Things are not always as they appear, especially in the case of Dee Dee and Gypsy Rose, and what starts out as a grisly tale of matricide morphs into a rabbit hole of deception. Child abuse, mental illness and forbidden love converge in this mystery of a mother and daughter who were thought to be living a fairy tale life that turned out to be a living nightmare.