At 8, was chosen to play an orphan in a 2000-01 national tour of Annie, and eventually starred in the title role in several productions
Made her Broadway debut in 2003 as Baby Louise in the Tony Award-nominated revival of Gypsy, starring Bernadette Peters and directed by Sam Mendes
In 2004, helped organize a reunion of Annie touring veterans for a production of the musical in Harleysville, PA, to benefit the Cystic Fibrosis Foundation and Children's Hospital of Philadelphia
After she got the part in Gypsy, her mother moved her and her siblings to Manhattan—where they lived for a time on Addison's $70,000 Broadway salary—so she could pursue her acting career
Made film debut in Derailed (2005) as the daughter of Clive Owen and Melissa George's characters
Appeared in the video for "Check Yes Juliet," a song by Florida pop-punk band We the Kings from their 2007 self-titled debut album