Melania Trump used newfound leverage to redo prenup after election win, new book says

First Lady Melania Trump favorably renegotiated her prenuptial agreement after husband Donald Trump won the White House, according to a new book by Washington Post reporter Mary Jordan.

Melania Trump stayed in New York for months after the president's inauguration, saying publicly it was because she didn’t want to interrupt son Barron’s school year. Privately, Jordan writes in "The Art of Her Deal: The Untold Story of Melania Trump," she was using the time to cool off and leverage her absence in her negotiations — as the president's allies wanted her in Washington to be a calming force for the president.

Jordan writes that Melania Trump had learned new details about her husband from the scandal-riddled campaign, which was marked by reports on the president’s alleged infidelities and a hot mic tape that captured Trump describing groping women's genitals and kissing them without consent, according to a Post report on the book. Trump has denied the affairs.

Melania Trump then used her standing as the president's longest relationship, and the first lady, to rework her initial prenuptial agreement, which the book reports had not been particularly generous.

Melania Trump's nearly six month stay in New York as first lady wasn't cheap: reportedly, her military flights to Washington cost hundreds of thousands of dollars, while guarding her and Barron cost the city millions.

Melania Trump referred to the prenup renegotiation as "taking care of Barron," the author writes, according to the Post report, and she sought written assurances that her son would be treated like the president's oldest three children with his former wives when it came to inheritance and financial opportunities.

Jordan’s book, the Post reports, paints a picture of an ambitious Mrs. Trump who embraced and encouraged the president’s political ambitious and is committed to winning a second term for her husband.

In a statement, the first lady's chief of staff, Stephanie Grisham, said, "Yet another book about Mrs. Trump with false information and sources. This book belongs in the fiction genre."

NBC News has not independently confirmed the reporting in the book, which is set to be released Tuesday.