Harris' family moved to Port Orange, Florida when she was in the fourth grade, where she attended Spruce Creek Elementary School. However, her tenure there was short-lived after winning a children's beauty contest which took her to New York. When in New York, Harris began her professional career by appearing in television commercials while maintaining an A average at PS 117 and PS 232 in Queens, New York. Her first acting role soon followed in 1985, when she made her debut as Sammi Garretson on ABC's One Life to Live, a role she played for three years.

In 1988, she auditioned for and won the part of Jamie Lloyd (Michael Myers' niece) in the movie Halloween 4: The Return of Michael Myers. Just one year later, she would reprise the role in Halloween 5: The Revenge of Michael Myers. The character of Jamie returned in 1995 for Halloween: The Curse of Michael Myers but Danielle did not due to disagreements on her fate in the script. Also, Harris requested $5000 to appear in the fil