You can watch video of the tense moment, which happened Monday in Carson City, Nevada, above.
Trump has faced criticism from both Republicans and Democrats for his statements about the Khans, who appeared at the Democratic National Convention to speak out against Trump. Their son, Captain Humayuan Khan, was killed in Iraq in 2004.
The woman, who gave her name only as Katherine, said her son is serving in the Air Force.
“Time and time again, Trump has disrespected our nation’s armed forces and veterans and his disrespect for Mr. Khan and his family is just an example,” she said, drawing boos from the crowd.
As Pence waved for the crowd to quiet down, Katherine continued her question, saying, “You have a son in the military, how do you tolerate this disrespect?”
Pence thanked the woman for asking the question as the crowd continued to shout at her.
“Folks, that’s what freedom looks like and that’s what freedom sounds like,” Pence said. “First I want to honor your son’s service to the country and your family’s service.”
Some in the crowd applauded that statement, as Pence then turned toward the Khan issue.
“As I said last night, and as Donald Trump said, Captain Khan is an American hero and we honor him and honor his family,” Pence said, again drawing applause. “The story of Captain Khan is an incredibly inspiring story.”
According to Politico, Pence went on to say, “I have never been around someone more devoted to the armed forces of this country,” about Trump. He said he has also not been around anyone “more devoted” to American veterans.
Pence then talked about Trump’s claims that he will reform the VA.
One of the rally attendees who booed the mother, Barbara Weisenthal, 56, told Politico, that Khan did not have the “right” to talk about Trump the way he did at the DNC, echoing the statements of the candidate. She also said Khan’s speech was “almost like slander.” She said it wasn’t the right place for the woman to ask her question.
Another Trump fan, 29-year-old Roen Horn, told Politico the Air Force mom was “claiming that Trump was somehow insulting the veterans,” and said that is “a bunch of crap. She was politicizing the veterans. She had an agenda.”