Grodstein was born on November 19, 1975, in New York City. She was raised in a Jewish family by her mother Adele, a Painter, and her father Gerald, a physician. She has a younger sister and a younger brother. She currently lives in Moorestown, New Jersey with her husband Ben, a musician, their son Nate and daughter Penny, and her Bernese Mountain Dog. She wrote a New York Times article on October 31, 2009, entitled "Take Me to the Election" in which she talks about New Jersey's upcoming gubernatorial election and the challenges of discussing it with her class.