Many will remember Ivanka's unwavering presence at her father Donald Trump's side throughout his presidential campaign and after. In a new biography about Mrs. Trump, The Art of Her Deal, Pulitzer Prize-winning Washington Post reporter Mary Jordan details the first lady's rivalry with her stepdaughter, who supposedly made a grab for power after her father's election. (Excerpts from the book, set to be released on Tuesday, have been published by The Washington Post.)
According to Jordan, who based her book off more than 100 interviews, Trump's victory in the 2016 election came as a surprise to him, so much so that he had made plans to go golfing in Scotland "immediately after the election so he didn’t have to watch Hillary Clinton bask in her success."
When the election results came in and Trump was declared president, he and his wife had to quickly adjust to their new roles. The mother of one, 50, chose to do so while remaining at their luxury Trump Tower penthouse in New York City with their son, Barron. The move was used as leverage to renegotiate her prenuptial agreement with her husband, according to Jordan.
In her early absence at the White House, Ivanka, 38, was appointed as an adviser in her father's administration, working out of the West Wing. During that time, "staff positions and budgets that would have been available to support the first lady’s office" were "diverted to support those in the West Wing, including Ivanka."
Trump's eldest daughter reportedly even tried to get her presidential father to rename the “First Lady’s Office” the “First Family Office.”
Jordan also claims Mrs. Trump "did not allow that to happen," writing that the first lady set up "firm boundaries" with her stepdaughter, who had allegedly made herself too comfortable at the White House.
"[Ivanka] treated the private residence as if it were her own home," Jordan writes. "Melania did not like it. When she and Barron finally moved in, she put an end to the 'revolving door.' "
In addition, Jordan declares Mrs. Trump as her husband's "single most influential adviser" at the White House.
“Melania is very behind-the-scenes but unbelievably influential. She is not one to go in and say, ‘Hire this person, fire this person.’ But she lets the president know what she thinks, and he takes her views very seriously," Sean Spicer, the president’s first communications director, told Jordan.
Some insiders also told the author that Mrs. Trump's input has become "something of a loyalty test" for Trump, who will ask his advisers: "This is what Melania thinks. What do you think?"
As news of Jordan's book was made public last week, the first lady's spokeswoman and chief of staff, Stephanie Grisham, dismissed the work as "fiction."
"Yet another book about Mrs. Trump with false information and sources," Grisham told PEOPLE in a statement. "This book belongs in the fiction genre."
The Art of Her Deal, which also digs into Mrs. Trump's earlier life, education and how she first met her future husband, is set to be released on Tuesday.