In sixth grade, Heather D. Heyer, the woman killed during the recent unrest in Charlottesville, Va., got into a heated dispute with a classmate who challenged her to a fight after school.

Ms. Heyer’s mother, Susan Bro, said in an interview on Friday that her daughter turned to her for advice, and that she transformed the confrontation into a teachable moment.

“She said: ‘Mom, I’m not a fighter. What am I going to do?’” Ms. Bro recalled. “And I said, ‘You know, you talked your way into this, you need to go talk your way out of this.’ And she and the girl later became fast and hard friends for a number of years.”

Now, through a foundation bearing her daughter’s name, Ms. Bro wants the country to learn the same lesson she taught her daughter: Disputes that careen toward violence can be de-escalated by communicating in a peaceful tone, not compromising personal values and, sometimes, agreeing to disagree.