She previously served as a judge of the State Bar Court of California from 2016 to 2024.

Valenzuela Dixon earned a Bachelor of Arts from the University of Arizona in 1991 and a Juris Doctor from the UCLA School of Law in 1995.

From 2006 to 2011, she was the head of national litigation at the Mexican American Legal Defense and Educational Fund in Los Angeles; from 2011 to 2016, she worked as the Criminal Justice Act Supervising Attorney for the Central District of California in Los Angeles.

President Biden nominated Valenzuela Dixon to the seat vacated by Judge Philip S. Gutierrez, who subsequently retired on October 22, 2024.

[5] On November 20, 2024, the United States Senate invoked cloture on her nomination by a 50–49 vote.