Sophia Saiz was last seen Friday morning at around 10:50 a.m. in the 1700 block of East Avenue J, according to the LASD.
She's described as 5-feet-2-inches tall and weighing 135 pounds with brown eyes and brown hair.
Sophia was last seen wearing a blue sweater, light blue pants and black shoes.
Anyone with information regarding Chavez's whereabouts was urged to call the sheriff's Lancaster station at 661-948-8466 or the sheriff's missing persons bureau at 323-890-5500. Those who wish to remain anonymous can call 800-222-8477 or visit lacrimestoppers.org.
City News Service contributed to this report.