She founded the band Evanescence with Ben Moody. The two met at a youth camp when Lee was playing Meat Loaf's "I Would Do Anything for Love" on the piano.

Lee was born in Riverside, California. She has a brother and two sisters. At school, Lee was president of the choir council, and appeared in a number of plays. Her family moved to many places, including Illinois, Kansas, and Florida, but finally settled in Little Rock, Arkansas, where Evanescence started. She graduated from Pulaski Academy in the year 2000. She also briefly attended Middle Tennessee State University.

Since May 2003, she has been in a relationship with Shaun Morgan of the band Seether, and sings with him on Seether's song "Broken".