Charlotte is a middle-aged woman who has worked for the CIA for 23 years. It is unknown how she knows Elizabeth or for how long. Charlotte has a 19-year-old daughter, a political science college sophomore at Emory University, who wants to work at the CIA like her mother.
Her motivation for helping the KGB is learned after she describes her one foreign-posting in Nairobi. Charlotte met with an asset and got more in one meeting than the asset's usual handler had in six months. Her report earns her top marks and praise, but she is over-looked for promotion, which instead goes to the ineffective handler.
After passing Elizabeth the list, she regrets her betrayed and calls the FBI. Attempting to stall Elizabeth, she pleads with her to stay a little bit longer, which causes Elizabeth to grow suspicious and make a hasty exit.