Violet Palmer became the NBA’s first woman referee when she worked Dallas’ opener at Vancouver on Oct. 31, 1997, and Sarah Thomas was the NFL’s first woman on-field official when she served as line judge for Kansas City’s game at Houston on Sept. 13, 2015.

MLB will call up its first female umpire over the weekend, with Jen Pawol scheduled to work both games of a doubleheader Saturday between the Miami Marlins and Atlanta Braves. Pawol, a 48-year-old West Milford, N.J., native, will also umpire Sunday’s game behind home plate calling balls and strikes.

Jen Pawol is set to become the first woman to be an umpire in a regular-season Major League Baseball game this weekend, working for the Atlanta Braves' three-game series at home against the Miami Marlins beginning on Saturday.