After being scouted in a shopping mall at age five, she began acting in commercials. She made her debut film appearance in the 1996 movie Santa with Muscles.
She starred in the movie The Social Network, and won the 2001 Young Artist Award for Best Performance in a TV Movie for The Ultimate Christmas Present.
She has two younger brothers named Timmy and Nathan. She was once engaged to Trace Cyrus, but the couple ended their relationship before they wed. In 2017, she began dating former child star Macaulay Culkin. Their first child together, a son named Dakota, was born on April 5, 2021. The couple became engaged in January 2022. They had a second child in late 2022.
She became friends with Ashley Tisdale, whom she met on the set of Bette.