Melania Trump caught on tape slamming her husband Donald and step daughter Ivanka

First Lady Melania Trump. Photo / AP

A former friend and adviser to Melania Trump has reportedly recorded the First Lady making "disparaging remarks" about her husband and some of the Trump children.

That news comes via Yashar Ali, a contributor to New York Magazine and The Huffington Post.

Stephanie Winston Wolkoff, an event planner, fell out with Mrs Trump after she helped produce President Trump's US$107 million inauguration in 2017.

The event was dogged by allegations of funds being misused – there was even a federal investigation into it – and Wolkoff felt she was made a scapegoat for decisions made by Mr Trump and his staff.

Now she is releasing the gazillionth tell-all book of the Trump presidency, which is titled Melania and Me: The Rise and Fall of My Friendship with The First Lady.

It's scheduled to be published on September 1.

According to Ali, the book includes comments Mrs Trump made slamming several members of the Trump family, including the President.

US President Donald Trump, first lady Melania Trump and their son, Barron Trump, arrive at the White House. Photo / AP

"It's unclear what exactly Wolkoff is alleging that the First Lady said about the President and his adult children, but two sources familiar with the contents of Melania and Me confirmed that she reveals the details in her book, including harsh comments about Ivanka Trump," he reports.

"I'm told by sources that the published comments are based on audio tapes."

This comes a few days after it emerged that Mr Trump's niece, Mary Trump, had secretly taped his sister, Maryanne Trump Barry, while she made scathing remarks about the President.

And if you think that's too many Trumps to keep track of, just wait until the convention speeches start. Over the next few days, we're going to hear from Donald, Melania, Ivanka, Donald Jr, Eric, Tiffany and Lara.