Serena Williams and husband Alexis Ohanian visit royal baby at Frogmore Cottage

Tennis superstar popped in to see baby Archie at Frogmore Cottage last week, making a flying visit before heading to Paris to compete in the French Open. 

Ms Williams, 37, was joined by her husband Alexis Ohanian, 36, and their one-year-old daughter Olympia. 

The seven-time Wimbledon champion, posted a picture of herself in a regal state room at the Windsor home of Harry and Meghan, who she is close friends with, the Daily Mail reports.

Ms Williams was a guest at Meghan's wedding to Prince Harry, and reportedly co-hosted her £330,000 baby shower in New York in February. 

The tennis star was helped in her hosting duties of the glitzy event by Meghan's best friend, Canadian fashion stylist Jessica Mulroney, 39, and the Duchess's sorority sister Genevieve Hillis. 

The event was held in the The Mark hotel's incredible Grand Penthouse Suite, which costs a staggering $75,000 per night, making it the most expensive hotel room in the US.