In 1998, she won a Young Artist Award for her role in the television movie The Right Connections. She was also nominated that year for a guest appearance on the series Sabrina, the Teenage Witch, which her sister Melissa Joan Hart starred in. A later episode of that series, entitled "Witchright Hall", served as a pilot for a possible spin-off series starring Hart as Sabrina's younger cousin Amanda, but the show was not picked up by the WB.
In 1999, Hart was cast in the title role of Sabrina: The Animated Series while her older sister Melissa co-starred as Hilda and Zelda Spellman, for which she was nominated for Young Artist Awards in 2000 and 2001, winning the second of the two. Also in 2001, Hart starred as the teen-aged Shirley Temple in the TV movie Child Star: The Story of Shirley Temple.
In 2003, she won another Young Artist Award for a guest appearance on the series Sabrina, the Teenage Witch.
In 2005, Hart starred in a 15-minute short film entitled Mute, directed by her older sister Melissa. Hart played York in the 2009/2010 horror thriller film Nine Dead, which also featured her older sister Melissa. In 2016 Emily was the narrator for the audio book of "Things I Can't Explain: A Clarissa Novel".
