Gabriel began her career in musical theater. She made her screen debut with the short filmIn Memoriam (2011), and played Laney Rucker in the action filmThe Purge: Election Year (2016). She earned critical acclaim for starring as Georgina in the horror film Get Out (2017), a performance which The New York Times called one of the best of 2017. She has portrayed Nari in the horror film Unfriended: Dark Web (2018), Detective Cortez in the cyberpunk filmUpgrade (2018), Deeks in the drama film Adopt a Highway (2019) and Joyce in the horror film It Lives Inside (2023).
After doing a bit of theater at Iowa State University,[9] Gabriel got her start working as an actress and dancer in Chicago theater, first as part of her further studies, and then in various productions.[6][10] Gabriel's first film role was in the 2011 drama In Memoriam.[1] She began her career as a television actress with minor recurring roles in Good Girls Revolt and Westworld before landing her first major film role in the 2016 horror sequel The Purge: Election Year.[4][11] Gabriel's character allows viewers to consider whether "the American dream" has become "the American nightmare" for many African-Americans, much as in her 2017 film Get Out.[12][13]
Gabriel was on vacation when she was invited to audition for Get Out. To prepare for the role, Gabriel watched the TEDx talk of Martin Pistorius to get insight into the feeling of being trapped inside one's own body.[14] She also watched Bride of Frankenstein and talked to her own grandmother, who was raised in Alabama, about racial tensions from her era.[15] The film was a critical and commercial success, and Gabriel earned critical acclaim for her performance. Her role was discussed as a contender for Best Supporting Actress for the 2018 Academy Awards by Variety and The New York Times.[16][17]The New York Times cited her role as Georgina as one of the best performances of 2017.[18]
Gabriel starred opposite Logan Marshall-Green in the sci-fi action horror film Upgrade (2018), written and directed by Leigh Whannell, and shot on location in Melbourne, Australia.[19][20][21] In 2017, Gabriel joined the cast of Westworld as the character Maling.[22] In February 2018, it was announced she would join the second season of Counterpart playing an FBI agent.[23]
In March 2021, Gabriel had a role in the animated horror film The Spine of Night, written and directed by Philip Gelatt and Morgan Galen King.[24] Later in August 2021, she continued her career in the horror genre by playing the role of Sophie Brewer in the Netflix miniseries Clickbait (2021), co-written by Christian White and Tony Ayres,[25] and despite the miniseries receiving a 59% on Rotten Tomatoes,[26] it received 1.46 billion minutes of watchtime in one week following its debut.[27]
Gabriel also appeared in the Apple TV+ limited series Manhunt,[28][29] as well as having a recurring role in the TV series Jack Ryan for its third season[30] in 2022.