Natalie Teeger became Adrian Monk's assistant after his former assistant, Sharon Fleming, moved to New Jersey to be with her ex-husband again. She is first introduced in the episode "Mr. Monk and the Red Herring", when two men break into her house in the same week. After she kills one in self-defense, she hires Adrian Monk to help her with the case. During the course of the investigation, Monk proves to be an honorable and kind man who'd make for a much better employer than the bar owner she worked for at the time, and she becomes Monk's assistant.
Natalie Teeger slowly learns to work with Monk and becomes really close with him, considering him a close friend and even stating she loves him in a friendly manner. Natalie even starts to pick up some detective instincts of her own and is often instrumental in helping solve the case. She is noticeably more laidback and patient with Monk than Sharona was, though not afraid to call him out when she feels he's being unfair or unreasonable. She's also slightly more formal with Monk than Sharona was, as she calls him "Mr. Monk" while Sharona called him "Adrian."
Natalie comes from an extremely wealthy family, as they run a large and very successful toothpaste company. However, Natalie refused to live the upper- crust life of her family or accept any kind of financial support from them, preferring to get by and make a living on her own.
Before becoming Monk's assistant, Natalie was married to Mitch Teeger, a Navy pilot who was shot down in Kosovo in 1998. She held several jobs, including bartending, which she quit after becoming Monk's assistant. Natalie has one daughter, Julie Teeger, whom she loves unconditionally and values above everything else in her life.