After high school, Brianne studied drama at New York University's Tisch School of the Arts, where she "started looking at [acting] in a different lens," as she told Cliché Mag in April 2015. At NYU, Brianne appeared a handful of short films, including Suckerpunch, Appropriate Sex, and Party Favours, among others. Before graduating a semester early in 2011, Brianne even booked her first-ever TV role.
"My first audition was for the CW's 90210," she revealed to The Chic Spy in September 2016. "I remember being very nervous and showing up way too early. I went in for the role of 'Girl in Green' and ended up booking a different role with a name, Stacey." Her character appeared in episode four of season three, and though it was a small part, it was enough to kick off her career.