Smith started her career in 1972 as a model, working for such brands as Chanel, Versace, Geoffrey Beene, Issey Miyake, Norma Kamali, Thierry Mugler, and Patrick Kelly. She also modeled for her brother Willi Smith’s brand WilliWear Ltd.

She also had a successful print career, including a photo campaign for Yves St. Laurent as well as appearances in the magazines Vogue, ELLE, Ebony, Cosmopolitan, Redbook, and Seventeen. In 1978, Smith was named Bloomingdale’s Model of the Year and became the second African–American model to have a mannequin designed in her likeness. Besides 227, her other credits include Talkin’ Dirty After Dark (1991), Joe’s Apartment (1994), and The Preacher’s Wife (1996). Smith had a restaurant in the West Village neighborhood of New York City called Toukie’s.

From 1985 to 1996, Smith’s long–term partner was actor Robert De Niro, with whom she had twin sons (Aaron Kendrick De Niro and Julian Henry De Niro, born 1995) conceived by in vitro fertilization and delivered by a surrogate mother. Smith said that the name “Toukie” comes from her grandmother, who used to play her a song about a fire engine that had a lot of energy. She now resides in NYC in Battery Park City.