When she was in sixth grade, Sandra Parks wrote an award-winning essay about gun violence and crime in her hometown, Milwaukee.

This week, two years after she described how “we are in a state of chaos,” she was fatally shot when someone outside fired a gun at her home and a stray bullet went into her bedroom.

The shooting happened Monday as Sandra, 13, was watching television at the time, her sister, Tatiana Ingram, told the television station WISN.

“My sister took it like a soldier: She just walked in the room and said, ‘Mama, I’m shot,’” Ms. Ingram said. “She was only hit one time, in her chest. The bullet wasn’t even for her.”