Louise Linton, wife of Treasury Secretary Steven Mnuchin, made headlines after posing with Mnuchin in front of a sheet of new $1 bills Nov. 15. This wasn't the first time she caused controversy. (Elyse Samuels/The Washington Post)

Louise Linton, wife of Treasury Secretary Steven Mnuchin, apologized Tuesday for boasting about her wealth and then disparaging someone who criticized her during a nasty social-media exchange in an attempt to quell a raft of criticism about her insult-laced attack.

“I apologize for my post on social media yesterday as well as my response,” she said, according to a publicist. “It was inappropriate and highly insensitive.”

Linton, an actress and producer, married Mnuchin two months ago in a lavish ceremony that was attended by President Trump and Vice President Pence. She often travels with Mnuchin on official business, which is not customary for the spouse of a Cabinet member, but Treasury Department officials have said the couple reimburse the government for the cost of her seat.

However, Linton drew attention Monday for posting a photograph of herself disembarking from a government plane with Mnuchin. In the post, she noted the clothing she was wearing at the time, made by various fashion designers including Hermes, Tom Ford and Valentino.

This drew an online comment from someone with the Instagram identity “jennimiller29,” who wrote, “Glad we could pay for your little getaway.” Linton responded to this with a fiery attack.

“Did you think this was a personal trip?!" Linton wrote on her Instagram page.

She added: “Adorable! Do you think the US govt paid for our honeymoon or personal travel?! Lololol. Have you given more to the economy than me and my husband? Either as an individual earner in taxes OR in self sacrifice to your country? I’m pretty sure we paid more taxes toward our day ‘trip’ than you did. Pretty sure the amount we sacrifice per year is a lot more than you’d be willing to sacrifice if the choice was yours.”

Linton added, “You’re adorably out of touch. … Thanks for the passive aggressive nasty comment. Your kids look very cute. Your life looks cute.”

Linton and Mnuchin recently returned from their honeymoon. Because Mnuchin is a Cabinet member, he would have had an extensive government security detail with him during the trip. It could not be learned whether the couple reimbursed the government for that cost.

Linton on Monday was accompanying Mnuchin on a trip to Louisville so the treasury chief could discuss ways to cut taxes for the middle class and so he could tour Fort Knox. Critics of Mnuchin’s tax plan have said it would benefit the wealthiest Americans much more than middle-income Americans.

Treasury secretaries typically fly on commercial airlines when they travel domestically, but they can get a waiver from the White House that allows them to use a government plane. A Treasury Department spokesman said the White House signed off on the logistics of this trip to Kentucky. In the photo Linton posted on Instagram, she is seen exiting the plane, which is painted blue and white and has “United States of America” emblazoned on the side.

Linton’s social media posts Monday ignited a raft of controversy and drew national media attention. The spouses of Cabinet members are often shielded from public scrutiny, but they also tend to keep a low profile. The spouses of recent treasury chiefs rarely traveled on official business with their husbands, and there is little precedent for a social-media fight such as this.

Linton's Instagram episode came in the midst of a strange period for Mnuchin, who two days earlier sent a letter to his former Yale University classmates explaining why he would not resign from office. They had called on Mnuchin to step down because of comments Trump made following a female counterprotester's death in Charlottesville at the scene of a violent rally held by white supremacists and neo-Nazis. Trump's comments after the rally expressed some sympathy for some of the people marching with the white supremacists.

In the statement Mnuchin issued, one week after the violence in Charlottesville, he said he condemns “the actions of those filled with hate and with the intent to harm others.” Mnuchin's statement stood out in part because other members of Trump's Cabinet issued statements condemning the white supremacists almost immediately.

Mnuchin is playing a central role in the White House's effort to overhaul the tax code and raise the debt ceiling, and the recent distractions have the potential to overshadow his work in those areas.

Jennimiller29, the Instagrammer who was on the receiving end of Linton’s social-media attack, had some choice words for the treasury secretary’s wife, saying in another post, “She says she’s a nice person. I doubt it.”