Cohan best known for her role as Maggie Rhee on "The Walking Dead" (2011–present). She is also known for her recurring roles on the television series "Supernatural" (2007–2008), "Chuck" (2011) and "The Vampire Diaries" (2010–2012), and in the comedy movie "" (2006), the psychological thriller "The Boy", and for her role in the DC Extended Universe as character Martha Wayne in "" (2016).