She became known as Mary Camden on TV's 7th Heaven and won a Young Artist Award for Best Performance for her supporting role in Ulee's Gold. Her well-known film credits include Summer Catch, Blade: Trinity, and The Texas Chainsaw Massacre.
When she was 12, she attended the International Model and Talent Association and began modeling in advertisements and commercials.
She won a Newport Beach Film Festival Award for her performance in the 2006 film The Illusionist.
She began dating Justin Timberlake in 2007, and the couple put on wedding bands on October 19, 2012. She gave birth to a son named Silas on April 11, 2015. She and Timberlake welcomed a second son in July 2020.