Susan Carter was an American who worked at the American embassy in London, although her parents lived in Minnesota. She appears in "As Good As It Gets".
As part of an elaborate scam involving the team tricking four different marks with the same con- precise details varied, but all the marks were convinced that they needed to loan money to the team's current identities to help them bribe the American ambassador to Thailand to receive greater profits later-, the team made contact with Susan posing as CIA agents.
Claiming that they needed her help for a mission of vital importance to America's future, they convinced Susan to loan them a room in the embassy for two hours so that they could meet with the four marks and receive their payment, Susan being instructed to direct the relevant guests to the room when they asked for 'Mr Powell'.