Pippa Middleton is selling her bike, which she recently used in a race across America, in aid of the British Heart Foundation.
The party planner saw the royal wedding as a "normal family" event and said the focus on her bridesmaid dress was "completely unexpected".
Boris Johnson has said that he is "very nervous" about playing Pippa Middleton at ping-pong after she challenged him to a match.
Pippa Middleton has filmed her first ever TV interview with US network The Today Show.
In a teaser video featuring the Duchess of Cambridge's 30-year-old sister, host Matt Lauer billed the hour-long interview as a preview of "what it's like to be Pippa."
Lauer joked that he had to fly to London to speak to the party planner, with Middleton replying: "I hate to say it but I was actually in America last week," laughing as she added, "Sorry."
The interview, which will be aired in two parts on Monday and Tuesday next week, will also cover Middleton's recent 3,000-mile charity bike ride across the US.
The Duke of Cambridge attended the wedding of his close friend James Meade to Lady Laura Marsham without his wife or son today.
However, Prince Harry and Pippa Middleton were among the guests at the wedding in Gayton, Norfolk.
They were taken by tractor trailer to the church ahead of the bride, who walked from the neighbouring country home of her father, Julian Marsham, the 8th Earl of Romney, who was at her side.
But she has written in The Spectator: "Team Johnson insisted that the match should be held at a venue of their choosing.
"I said by all means. And then — nothing.
"The Spectator has tried to follow up, but now it’s radio silence from the Mayor’s office. Is Boris scared or what? He should be."
Pippa Middleton has revealed how she was left embarrassed at Wimbledon after her father mistakenly cheered on Pete Sampras instead of British hopeful Tim Henman.
Writing for magazine Vanity Fair, she said: "When Tim Henman walked on to the court, the crowd cheered him, and as he walked near our seats my dad mistakenly yelled 'Come on Pete'."
Ms Middleton also recalled queuing for the Championships with her older sister, the Duchess of Cambridge, on People's Sunday in 2004 to get £35 Centre Court tickets.
Pippa and James Middleton are watching the tennis at Wimbledon from in the Royal Box on Centre Court during day one of competition.
@frasernelson I’m game if she is. Happy for Pippa to join me on a visit and see the benefits of our £22m Sports Legacy Fund in action
The Mayor of London has accepted Pippa Middleton's challenge to a game of table tennis to crown the "whiff-whaff king."