The youngsters – ages 10 and 8 – dined with mom Michelle Obama at The Audley on Mount Street in Mayfair on Monday evening in a move that caught bar managers by surprise.
The children chose the fish supper while their mother opted for sirloin steak, say the pub's owners, Punch Pub Company.
"We were all speechless when they walked in," said Cintia Pinto, 24, who served the first lady's table. "I couldn't believe it. But they were all very friendly, smiling and laughing."
"They made us feel calm. The girls were so sweet and polite. They thanked us every time we brought them something. It was a real honor," says Pinto.
The group dined in the pub's private dining room upstairs, managers say, and before long a crowd gathered outside, clamoring for a view of the special visitors.
"We've had other famous people coming in," manager John Gohery said, "but nothing on this scale."
Big Ben and ParliamentEarlier in the day, the girls also visited the set of the new Harry Potter movie at North London's Pinewood Studios and the Houses of Parliament, where they checked out the historic clock tower and its Big Ben bell, according to the BBC.
Mrs. Obama also met with Sarah Brown, the wife of Prime Minster Gordon Brown – someone she got to know well during her last visit to London back in April, when she accompanied her husband on a royal visit.