The Arizona Cardinals have hired Jen Welter to be an assistant coaching intern, working primarily with linebackers throughout the preseason. Welter, 37, is the first female coach in NFL history. But she is not new to football. She played the game for 14 years in a women’s pro league. In 2014, she became the first woman to play in a men’s pro league as a non-kicker. She played at running back and on special teams for the Texas Revolution of the Champions Indoor Football league. Welter then became a coach for the Revolution. The NFL also made history in April, when it hired Sarah Thomas to be the league’s first full-time female official.