Hillary said she and Bill ended up calling the Bushes and the Carters, both of whom said they'd be going.
"And the elder Bushes were in the hospital, which I think was legitimate," she said, eliciting laughs from the audience.
"I didn't know what to expect," she said of the event. "What I wanted to have happen was, despite the kind of campaign he ran, I wanted him to rise to the occasion of being our president, and being the president for everybody, not just people who supported him. That didn't happen."
Hillary recalled sitting next to George W. Bush, listening to Trump's "dark, divisive speech" that she described as "a cry from the white nationalist gut."
"It's reported that George W. Bush, as it ends, says, 'That was some weird sh-t,'" she said.
Norton then asked Hillary about her epic response to Trump's tweet regarding her book in which he said that "Clinton blames everyone and everything but herself for her loss."
Norton pulled up Clinton's response -- a picture of her children's book, "It Takes a Village," accompanied by the tweet: "If you didn't like that book, try this one -- some good lessons in here about working together to solve problems. Happy to send you a copy."
When asked if she's ever tempted to ignore Trump's tweets about her, Clinton replied, "I ignore a lot of them because there are so many."
She shamed the president for using the social media platform to "attack people" and "talk about issues that are very complex."
"The most dangerous thing he does is conduct diplomacy on Twitter," she said. "He is trading insults with Kim Jong-un, which is just like cat-nip for Kim Jong-un. He loves that -- the idea that he's in a Twitter insult fest with the President of the United States."
"He does things that are not only upsetting, but kind of inexplicable," she added.