But the past four years of singular loyalty to Trump, including defending him on TV and with informal "gaggles" with the press, have taken a toll on the combative spin doctor who coined the phrase "alternative facts."

While she made a name for herself as one of Trump's sharpest defenders, her husband, prominent Washington lawyer George Conway, is a strident critic of the president, repeatedly and loudly questioning his mental fitness for office.

"I will be transitioning from the White House at the end of this month," she said in a statement.

"George is also making changes. We disagree about plenty but we are united on what matters most: the kids."

She said their four children would be starting the new academic year remotely.

"As millions of parents nationwide know, kids 'doing school from home' requires a level of attention and vigilance that is as unusual as these times," she said.

"For now, and for my beloved children, it will be less drama, more mama."

Her announcement came a day after her 15-year-old daughter Claudia tweeted that she was "devastated" that her mother would speak at the Republican convention, and pledged to seek legal emancipation "due to years of childhood trauma and abuse."

'Alternative facts'

Separately, George Conway said he would be stepping back from the Lincoln Project, a group of anti-Trump Republicans he co-founded, and taking a break from Twitter, which he frequently used to assail the president.

The dislike was mutual, with Trump calling him the "husband from hell."

Kellyanne Conway came to prominence just days after Trump took office for coining the term "alternative facts" while defending the debunked White House claim that the 45th president's inauguration crowd was larger than Obama's.

In 2017 she referred to a non-existent terrorist attack, "the Bowling Green massacre," to defend Trump's immigration ban.

During Trump's term she was both famous and notorious for sparring with the media, often by finding a way to change the topic, turn the question back on the reporter, or merely complain.

She did all of it with a flamboyant fashion sense -- snake-skin pattern dress one day, a bright red one the next -- standing out in an often-gray city.

Her work led her at one point to be depicted on the long-running US comedy show Saturday Night Live as "Kellywise", a spoof of the murderous, sewer-dwelling clown from horror novel and film "It".

A lawyer and pollster by training, she also stuck out her White House role while a parade of other aides was forced out, quit or left in humiliation.

In her statement, Conway described her time at 1600 Pennsylvania Avenue as "heady" and "humbling" and said her departure was her call.

"This is completely my choice and my voice. In time, I will announce future plans."