Fort Worth police say 39-year-old Chanita Nichole Holly called her son from Saturday's game involving 8-year-old players, and that he later arrived and started shooting.
Police say a woman was struck in the leg and a girl was grazed in the back.
Holly was charged with making a terroristic threat after her arrest Monday night during a traffic stop.
Witnesses told police they heard an angry woman shouting that they were going to "spray" the crowd.
Holly couldn't be reached for comment. Her son, who hasn't been identified, hasn't been arrested.