Gardner was born in Los Angeles, California. She began acting on television at an early age, appearing in a recurring role on Viper and guest starred on ER. She later moved to New York City and graduated from the Juilliard School. In same time, Gardner began acting on stage and appearing in such productions like For Colored Girls, The School of Night, and The Seagull. She also has appeared in a number of regional productions. She had a number of guest-starring roles on television shows such as Crossing Jordan, Bones, Heroes and Castle. Gardner worked as a voice actress playing Steela Gerrera in the Star Wars: The Clone Wars. In 2016 Gardner was cast as a lead character in the Oprah Winfrey Network drama series, Queen Sugar.