When Sadie (Ambyr Childers), one of Charlie's girls, tries to con her way into friend Emma (Emma Dumont)'s home, she introduces herself to Emma's mom Grace (Michaela McManus) as Susan Atkins, a former co-ed of Emma. In actuality, Susan Atkins (1948-2009) was one of Manson's notorious clan who slaughtered 9 people in California in the summer of 1969. She was best known to the clan as "Sexy Sadie."