Stars of David are not red (blue border on white field); ghetto stars used by the Nazis were yellow; and the red star, among other things, is the shoulder badge of the US Army’s 6th Infantry Division. The six-sided star is part of the library of shapes in Microsoft Word and Paint, and it provides a nice big field to insert some derogatory phrasing.
Mandel got her gun and alerted local police, who now monitor her home. Mandel also wrote a piece for the Jewish Forward: "My Trump Tweets Earned Me So Many Anti-Semitic Haters That I Bought A Gun." It went viral.