In NY it is illegal to be a freelancing agent (including NYC). ALL real estate agents who are licensed need to sign a contract with a brokerage and the broker needs to keep their license while they are under their supervision. Brokers are legally responsible for their agent's actions.
Therefore, tell this freelancing agent that they are performing their business illegally and you will be using a different agent - one who has a contract with a broker. You can also check the New York State Licensing division website to research the agent's name, license number and brokerage they work for.