(CNN) President Donald Trump has a longtime habit in high-profile meetings that's no "Art of the Deal" secret: a casual drop-by from daughter Ivanka Trump.

Take Wednesday's meeting with congressional leaders: Ivanka Trump, who also serves as a White House adviser, "entered the Oval Office to 'say hello' and the meeting careened off-topic," a congressional source briefed on the meeting told CNN's Deirdre Walsh.

Some Republican leaders were "visibly annoyed by Ivanka's presence," the source said.

But House Speaker Paul Ryan spokeswoman AshLee Strong refuted that characterization, saying, "That's not true."

At the time she entered, the President had just sided with Democrats and agreed to support a deal that would ensure passage of disaster relief funding as well as raising the debt ceiling and continuing to fund the government into December, a senior GOP source told CNN's Dana Bash.

Ryan and Senate Majority Leader Mitch McConnell were already "shell-shocked" by what had just happened when she arrived, according to a senior GOP source.

But the first daughter walked into the Oval Office to talk specifically about the child tax credit, a key priority in her White House portfolio.

Marc Short, White House director of legislative affairs, confirmed the purpose of Ivanka Trump's visit.

"We asked Ivanka to briefly join the meeting for an update on the child care tax credit and how we are working to make tax reform a bipartisan issue," he said. "It was a quick and productive conversation."

Earlier in the day, she had participated in a meeting with Americans for Tax Reform alongside Sen. Mike Lee and others.

"I look forward to making this expanded Child Tax Credit a reality! Working parents deserve #TaxReform," she tweeted Wednesday morning.

1:2 Just concluded a great meeting on #TaxReform & the Child Tax Credit w/ coalitions supporting tax relief for American working families. pic.twitter.com/sj07COcW8P — Ivanka Trump (@IvankaTrump) September 6, 2017

Ivanka Trump also joined her father Wednesday afternoon in North Dakota, where he gave a tax reform speech.

In the middle of his remarks, the President brought her onstage.

"By the way, Ivanka Trump? Everybody loves Ivanka Trump," he said. "Come on, should I bring Ivanka up?

He added that his daughter had asked to join him on the trip.

" 'Daddy, can I go with you?' " the President said his daughter asked him. "I said, 'yes you can.' "

Ivanka Trump made brief remarks on stage before leaving the stage.

Art of the 'drop-by'

The President's eldest daughter has also dropped by media interviews in the Oval Office during the first months of the administration.

While Trump was speaking to The New York Times in July, Ivanka Trump and daughter Arabella Kushner popped in to say "hello" as he was answering a question about former FBI Director James Comey's testimony on Capitol Hill.

"His testimony is loaded up with lies, OK? But people didn't -- we had a couple people that said -- 'Hi baby, how are you?' " Trump said as his granddaughter entered the room.

"Just wanted to come say 'hi,' " Ivanka Trump said as she stood in the doorway, according to a transcript of the interview.

The President asked his granddaughter to say hello to the reporters in Mandarin, touting the six-year-old's "good, smart genes," before returning to the topic at hand.

Later that month, Ivanka Trump dropped by an interview the President was having with The Wall Street Journal.

"I heard you were here. I wanted to come by and say 'hi,' " she said, greeting Wall Street Journal editor-in-chief Gerard Baker, according to a transcript obtained by Politico.

"It was nice to see you out in Southampton a couple weeks ago," Baker told the first daughter, who praised his publication's recent "very nice editorial."

"Thanks, honey," the President said, adding, "Stay around if you want."

Well-practiced

But the Ivanka Trump drop-by is hardly a new tradition.

The first daughter told CNN's Gloria Borger in July 2016 during the Republican National Convention that she used to call the Trump Organization collect during her private school days at the Chapin School in New York City.

Hiding in a janitor's closet during recess, she would dial her dad, who would put her on speakerphone with whomever happened to be in his office.

"It was colleagues, it was titans of industry, it was heads of countries. He'd always tell everyone in the room how great a daughter I was and say cute things and ask me about a test I took," Trump had told Borger.

Now, as a senior adviser to the President, her drop-bys have considerably more weight.

Many first family members have had a West Wing presence -- Hillary Clinton even had a West Wing office while serving as first lady.

"It's complicated for staff because they know that, in the end, the family has the greatest influence over Trump and so what they say can be overruled as soon as they leave the room. They don't feel like they can be as honest when a family member is in the room," said Kate Andersen Brower, a CNN contributor and author of "First Women: The Grace & Power of America's Modern First Ladies."

"This relationship between father and daughter is even closer so it makes it even more difficult," Brower added.

CORRECTION: This story has been updated to correct Donald Trump's quote from "Daddy, can I come with you?" to "Daddy, can I go with you?"