Melania Trump’s chief of staff and press secretary Stephanie Grisham slammed the “false information and sources” cited in a Washington Post article, which states the first lady delayed moving to the White House after her husband was elected president to renegotiate her prenuptial agreement.

“Yet another book about Mrs. Trump with false information and sources,” Grisham told Fox News. “This book belongs in the fiction genre.”

When President Trump was first elected president, Melania and 10-year-old Barron Trump stayed behind in New York, so as not to pull their son out of school in the middle of the academic year, according to the first lady's office.

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But Washington Post reporter Mary Jordan writes in her forthcoming book, “The Art of Her Deal: The Untold Story of Melania Trump,” that Melania Trump delayed her move to the White House as leverage in renegotiating her prenup.

After allegations of affairs with adult film star Stormy Daniels and ex-Playboy model Karen McDougal, the stories of which did not become public until 2018, Jordan writes that Trump needed time to “cool off” and to “to amend her financial arrangement with Trump — what Melania referred to as ‘taking care of Barron.’”

Jordan writes of an “uptick” in Melania Trump’s mood in mid-2018, which three people “close to Trump” tell her was on account of Melania finally renegotiating her prenup to her liking. The original one had not been “incredibly generous,” Jordan writes.

She says Melania Trump had already ensured dual citizenship for Barron in Slovenia, which positioned him to work for the Trump Organization when he comes of age, but wanted the prenup to ensure Barron was equally included in the family business.

“She wanted proof in writing that when it came to financial opportunities and inheritance, Barron would be treated as more of an equal to Trump’s oldest three children,” Jordan writes.

Jordan writes that Melania Trump had bargaining power, as she’d been married to the president longer than either of his ex-wives. Her “calming effect” on Trump was so great that Trump’s cohorts and at least one of his adult children asked her to move to the White House as soon as possible.

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Still, Jordan writes that Melania Trump shares her husband’s political ambitions far more than many realize. “She is . . . much more like him than it appears,” Jordan says.

“There is ample evidence that from the very beginning,” Jordan writes, “Melania not only accepted and embraced Trump’s political aspirations but was also an encouraging partner.”

Jordan says that Trump ally Roger Stone, who is set to spend 40 months in prison on convictions of witness tampering and lying to investigators as part of the Mueller probe, told her the first lady is the one who encouraged Trump to run for president.

She writes that former New Jersey governor and Trump adviser Chris Christie told her Melania Trump is the president’s “sounding board,” the first one he called on the plane after a rally.

“She always had commentary to give him, and I think that tells a lot about what he thinks of her,” Christie said.

Jordan attributes Trump’s pick of Mike Pence for a running mate to Melania Trump. She argues that Pence would be a better choice than Christie or Newt Gingrich, according to Jordan. “She believed that he would be content in a number-two spot and not gun for the top job,” Jordan writes, “which was something she could not say about the other two.”

Fox News' Kristina Biddle contributed to this report.