"I think Donald Trump says a lot of things that are crazy," Fiorina responded.
Harrison's sister, Zahra, who is 10 years old, weighed in: "Donald Trump's a moron."
“There you go!" Fiorina replied. "Donald Trump’s a moron. Out of the mouths of babes.”
Zahra told ABC News that she was Muslim and disagreed with the businessman's proposal to ban the entry of Muslims into the United States. She came to Fiorina’s town hall with her father, a Fiorina supporter, and her two younger siblings.
“Donald Trump is a moron because he doesn’t support racial rights, because he’s saying that Muslims are bad and they should be kicked out of the country," Zahra said. "I don’t think that’s fair, because I’m a Muslim, my mom’s side is a Muslim, and it’s just not fair. You’re just judging a person by their religion and you’re not looking at their profile or looking at their status updates. Like, 'Have they been to jail?' 'Have they been a terrorist or not?'
"You gotta think about that," she continued. "You can’t just spit out words. I’m spitting out words, but I have a reason."
The Trump campaign did not immediately respond to ABC News' request for comment Friday.