Carlotta Stewart was born in Brooklyn, New York, where she attended public schools during her formative years. Although her father had spent several years in Liberia, Africa, Carlotta had never traveled outside of the continental United States. She was eighteen when she arrived in Hawaii in 1898, with her father and stepmother.
Stewart graduated from the Punahou School, Oahu College in 1902. After graduation, she completed the requirements for a Normal School certificate, which she received also in 1902, and promptly accepted a teaching position in the Practice Department of the Punahou Normal School in July, right after her graduation. Carlotta remained at the Normal School for several years where she taught English.
Steward made the decision to remain in Hawaii, and it turned out to be an advantageous one. By 1909 she had been promoted to principal of the Koolau elementary school. Stewart’s mobility in the space of seven years was an impressive achievement. While many black women had established careers in teaching and a handful as administrators by 1909, it was unusual for a black female at the age of twenty-eight to serve as principal of a multiracial school.
In 1916, she married Yun Tim Lai in Kauai County. Lai, the sales manager of Garden Island Motors, Ltd., an automobile dealership in Lihue, Kauai, was five years younger than his new wife. The marriage ended in 1935 when Lai died suddenly in Hong Kong while visiting relatives. Stewart never remarried.
By 1951, poor health forced Stewart to enter a Honolulu nursing home. Her health declined rapidly, and on July 6, 1952, she died.