Melania Trump channels Jackie-O in Ralph Lauren

First Lady Melania Trump on Friday channeled predecessor Jackie Kennedy as her husband took power, donning an elegant Ralph Lauren powder blue suit that won rave reviews -- and helped silence her critics.

Her cashmere turtleneck dress fell to her knee, paired with a cross-over jacket cropped to the waist and matching suede gloves. The 46-year-old former model wore her hair swept up, showcasing diamond stud earrings.

The look won gushing praise and provoked comparisons with Kennedy, the wife of slain Democratic president John F. Kennedy who was considered to be one of America's most stylish first ladies.

The fashion victory came one day after the Slovenian-born third wife of Donald Trump was widely thought to have been outshone by her stepdaughter Ivanka, who wore a cascading green Oscar de la Renta outfit on Thursday.

Ralph Lauren confirmed that Trump's outfit was custom-made.

Lauren, a 77-year-old master with a flagship boutique on New York's Madison Avenue, is perhaps America's most iconic living designer, inspired by European sensibilities but whose clothes define a uniquely American sense of elegance.

Together with her gown for Friday night's balls, the suit is likely to go on display at the Smithsonian's National Museum of American History along with first lady inaugural wear dating back to Mamie Eisenhower.

Trump has in the past been criticized for favoring high-end European clothes during her fleeting campaign and post-election public appearances.

She is America's second foreign-born first lady since England's Louisa Adams, wife of John Quincy Adams, who was president from 1825 to 1829.

A string of designers have refused to dress her because of her husband's controversial politics, making her sartorial debut on the world stage particularly scrutinized.

On Thursday, she wore a military-inspired black coat by Norisol Ferrari, a little-known New York designer of Hispanic descent and daughter of a wounded veteran.

- 'Revolutionary Wear' -

In the evening, she shimmered in a stunning golden gown from Reem Acra, a Lebanese-born American designer, for a candlelight dinner, which Vogue compared to the "classic glamour" of first ladies Nancy Reagan and Laura Bush.

Both choices gave nods to inclusivity at a time when her husband is under attack for divisive rhetoric and pre-inaugural threats to deport up to three million illegal immigrants.

The fashion choices of America's first ladies have become hugely influential, believed to send implicit messages about the tone of their husbands' administrations.

Their patronage can provide a major boost to business for design houses.

A study by New York University professor David Yermack, published in the Harvard Business Review in 2010, found that Michelle Obama's fashion choices had an unprecedented impact on a company stock price, eclipsing other fashion icons such as France's former first lady Carla Bruni-Sarkozy.

Trump has big shoes to fill in Obama, a darling of the fashion industry for her savvy blend of accessible high street clothes with striking high-end pieces that championed a host of little known designers.

Obama went back to Jason Wu, who designed both of her inaugural gowns, for her final outfit as first lady -- an understated red and black tweed jacquard dress with a matching double breasted coat.

As the wife of a billionaire, who will live in their Manhattan penthouse overlooking Central Park at least until their young son Barron finishes the school year, it remains to be seen whether she will follow Obama's example and include more accessible clothing from retailers such as J.Crew in her wardrobe.

She will also have to work hard to keep up with 35-year-old Ivanka, who unlike Melania is moving straight to Washington with her husband, Jared Kushner, an incoming White House advisor.

On Friday, Ivanka and her half-sister Tiffany both opted for timeless white coats, which while elegant allowed their stepmother to shine. Ivanka was again clad in Oscar de la Renta.

But the internet savaged one member of Team Trump: campaign manager and close presidential aide Kellyanne Conway -- panned for wearing a $3,600 red, white and blue Gucci coat that she dubbed "Trump Revolutionary Wear."

The patriotic A-line coat, which recalled the uniforms of the US Revolutionary War, was studded with feline metal buttons. Conway, who was simultaneously celebrating her 50th birthday on Friday, paired it with a bright red hat.

The look drew comparisons with Paddington Bear's blue coat and red sou'wester or, as "The Daily Show" quipped on Twitter: "Conway dressed as the era Trump wants to take America back to" next to a drawing of a Revolutionary soldier.