At just a few month old, Carmencita Johnson started appearing in the "Our Gang" shorts. As a child she appeared in some of the better-known silent features such as The Way of All Flesh (1927), The Winning of Barbara Worth (1926), and The Wind (1928).

In the 1930s and 1940s, she did some modeling, acted, and was an occasional stand-in for Lana Turner. She also swam in Esther Williams aquatic movies.

Her best-known scene was probably in the last movie she worked on, İnsanlık suçu (1951). Besides being one of Elizabeth Taylor's friends, Carmencita doubled for Shelley Winters when the Montgomery Clift character murders Alice Tripp by pushing her into the lake (or does he?) in İnsanlık suçu (1951).

Carmencita married Jack Robertson in 1949 and soon after retired from film work. They had four sons--Nicolas, Drew, Winslow, and Cullen--and a daughter, Sydney. In 1961, Carmencita and Jack moved to Ojai, California, where she became a tireless supporter of the arts and helped to establish the Ojai Studio Artists Tour and the Ojai Art Center.

She was selected Ojai Valley Woman of the Year in 1985, and was the longtime publicist for artist George Stuart.

A number of the films Carmencita appeared in have been "lost," including the Academy Award-winning movie The Way of All Flesh (1927).

On September 26, 2000, the Robertsons were traveling on Harbor Boulevard and turning onto Peninsula Street in Ventura when their 1990 Honda Civic was broadsided by a 1991 Chevrolet Blazer. The passenger side of their car, where she was sitting, received the brunt of the impact. She was taken to Ventura County Medical Center, where she died about five hours later.