Ivanka Trump Says She Will Not Be Filling In as First Lady in Trump Administration Ivanka, Don Jr. and Eric Trump sat down for exclusive interviews with "20/20."

 -- Ivanka Trump dispelled speculation that she will be filling in as a surrogate first lady or occupying the East Wing office of the White House, traditionally reserved for the president’s wife.

Speculation that Ivanka Trump will fill in for incoming first lady Melania Trump started swirling after Trump transition sources said Melania Trump was not expected to move to Washington, D.C., until the spring, after her and President-elect Donald Trump’s 10-year-old son, Barron, finishes the school year. But Donald Trump’s elder daughter said those speculations were “an inappropriate observation.”

“There is one first lady, and she’ll do remarkable things,” Ivanka Trump told ABC News’ “20/20” in an exclusive interview.

Ivanka Trump and her husband, Jared Kushner, have quickly ascended to become Washington’s new power couple. Last week Trump transition officials announced that Kushner was expected to serve as an unpaid senior adviser to the president, while Ivanka Trump’s role has not yet been formally announced.

Kushner is leaving behind his family’s billion-dollar real estate business, and Ivanka Trump is departing from her clothing and accessories brand that bears her name — both in an effort to comply with federal ethics laws, the legal and transition team advising the family told reporters last week.

Ivanka Trump will no longer be participating in the management of the Trump Organization, and she will resign from all office/director positions in her company brand. She will also divest significant assets, including common stock and restructure her participation in Trump Organization transactions.

“It’s emotional,” Ivanka Trump said. “I’m stepping away from my business ... My father will be president, and hopefully, I can be there to support him and to support those causes I’ve cared about my whole professional career.”

Ivanka Trump, whose new book, “Women Who Work: Rewriting the Rules for Success,” will be out in May, told ABC’s Deborah Roberts she will be donating the proceeds from it to charity.

Donald Trump’s two eldest sons, Donald Trump Jr. and Eric Trump, will not be making the move to Washington, Trump transition team officials said, and will remain in New York, entrusted with running their father’s vast business empire. It’s a move that has been slammed by critics who are concerned that the move doesn’t adequately guard against conflicts of interest, but Eric Trump stands by the transition plan.

“My father has the biggest responsibility of any person, arguably, on the planet, and that’s to run the United States of America,” he told “20/20” in an exclusive interview. “His focus is going to be running this country.”

The weight of that reality, assuming the role of commander in chief, is something Donald Trump Jr. believes might not yet have fully sunk in for his father.

“I don’t think anyone could become that cynical that wouldn’t affect him,” he told “20/20” in an exclusive interview. “Going around the country and seeing all these people who’ve been either disaffected from politics but have just been through so much — to be able to go through it and see them and talk to them ... it was just a culmination of, just, incredible and moving experiences.”