Brammell has had recurring roles on Six Feet Under, The Shield, Push, Nevada, and Star Trek: Enterprise.
In 2004, she received good reviews for her performance as Sabina Spielrein in the North American premier of Christopher Hampton's play, The Talking Cure, at the Mark Taper Forum in Los Angeles.
She also appeared in NCIS season 8 episode three, "Short Fuse", as Marine Sergeant Heather Dempsey.
She played Tamara Moor in the thriller Playdate (2012), a made-for-television film produced in the United States.
On October 11, 2015, it was announced Brammell would voice the female protagonist in Call of Duty: Black Ops III for Microsoft Windows, PlayStation 4, and Xbox One.