Meghan last watched her friend in 2016, and may have sat on the same court as her future sister-in-law, as Catherine and William also attended that year.
"In fact, I've probably forgotten about it", she added to a disbelieving audience.
There will be a couple of duchesses in attendance on Saturday.
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Serena gave birth to her first child, daughter Alexis Olympia Ohanian Jr, less than a year ago and if she wins Wimbledon, she'll be the first mother since 1980 to pick up the trophy.
She shared, "I am very hurt by a statement that has shown in the media and all over the online platform in the past few days". But a special little boy not only got to stand next to the Duchess of Sussex, he was also able to touch her face and hair. Williams first came back by playing doubles with her older sister, Venus, for the U.S. Fed Cup team in February.
Expressing her excitement to the interaction on Instagram, Chloe wrote "Ya girls artwork going in Kensington Palace Delighted to have gotten to talk to them and have them keep my drawing they're genuinely so nice!"
In a nod to her own wedding to Harry, a band outside played Stand By Me as the newlyweds spoke to the public outside the museum.
He explained: "I look forward to coming to London to meet them soon".
During the same interview, Williams was asked if she considers herself a Wimbledon royalty, and she said yes.