Katherine Herzer's professional career began when she was a child, cast in a Geico commercial singing the '70s pop hit "Kung Fu Fighting" from her car seat. Her first non-commercial screen role was as the 5-year-old version of one of the adult characters in an episode of "Without a Trace" (CBS, 2002-09). Unlike many child actors, Herzer did not appear in series regular roles until after she graduated from high school. This, however, didn't exclude her from working altogether. She maintained an on screen presence on the big screen and small. Minor roles in the features "A Lot Like Love" (2005) and the Brad Pitt and Angelina Jolie vehicle "Mr. And Mrs. Smith" (2005) convinced the young Herzer that she could to follow her passion. She continued appearing in small guest roles on "The Mentalist" (CBS, 2008-2015), and NCIS (CBS, 2003-), before returning to "Without At Trace" to play a different guest role in 2009, five years after her initial appearance. After a few more small TV roles and a supporting part in Jason Reitman's "Men, Women, and Children" (2014), Herzer landed her first series regular role in "Madam Secretary" (CBS, 2014-). On the show, she played the youngest daughter of the Secretary of State, played by Téa Leoni.