Last week, Ghazala Khan joined her husband, Khizr, onstage as he gave a powerful speech at the Democratic National Convention in Philadelphia The bereaved parents of Army Captain Humayun Khan spoke about their son's love of country and his sacrifice in Iraq. They also slammed Republican presidential nominee Donald Trump's offensive remarks about Muslim-Americans.Trump decided to respond to the speech by mocking the writer and questioning whether Ghazala Khan hadn’t spoken on the stage because, as a Muslim woman, her husband wouldn’t permit her to speak in public."If you look at his wife, she was standing there," he told ABC News . "She had nothing to say. She probably, maybe she wasn't allowed to have anything to say."On Sunday, Ghazala Khan fired back — saying, in part, "Donald Trump said he has made a lot of sacrifices. He doesn’t know what the word sacrifice means."In a Washington Post op-ed entitled, "Trump criticised my silence. He knows nothing about true sacrifice," Khan wrote that she did, in fact, have something to say. She shared the story of her son, Humayun, and spoke about life as a Gold Star mother.But most importantly, she shared why she was silent on stage."I cannot walk into a room with pictures of Humayun. For all these years, I haven’t been able to clean the closet where his things are — I had to ask my daughter-in-law to do it. Walking onto the convention stage, with a huge picture of my son behind me, I could hardly control myself," she wrote. "What mother could? Donald Trump has children whom he loves. Does he really need to wonder why I did not speak?"