Kate Middleton has been seen in public for the first time since the release of Prince Harry’s highly anticipated memoir, Spare.

The Princess of Wales, who celebrated her 41st birthday on Monday, was spotted driving a car near Windsor Castle on Wednesday morning.

It is the first time Kate has been spotted since Harry’s book was officially released on Tuesday. Both Kate and her husband, Prince William, are spoken about multiple times in the memoir — including an account from Harry that his wife, Meghan Markle, and his sister-in-law had a heated exchange in 2018 after Meghan referenced Kate’s “baby brain because of her hormones.”

Kate, who gave birth to her third child Prince Louis one month before the Duke and Duchess of Sussex’s wedding later that year, raised the conversation with Meghan, chiding her that discussing pregnancy hormones was too personal.

EXCLUSIVE: Catherine, Princess Of Wales, seen here for the first time since the release of ‘SPARE’ as she returns to Windsor Castle

In the book, the Duke of Sussex claims that Prince William pointed his finger at Meghan, saying that she made a “rude” comment. Meghan, in turn, was hurt by the reprimand.

Harry, 38, also discussed in the book how he felt like William was “gone — forever” after he married Kate, saying that the 2011 nuptials felt like “yet another farewell.”

A view of Prince Harry’s memoir ‘Spare’ on display at a bookshop in central London

Wiktor Szymanowicz/Anadolu Agency via Getty Images

“The brother I’d escorted into Westminster Abbey that morning was gone — forever,” Harry wrote. “Who could deny it? He’d never again be first and foremost Willy. We’d never again ride together across the Lesotho countryside with capes blowing behind us. We’d never again share a horsey-smelling cottage while learning to fly. Who shall separate us? Life, that’s who.”

“And I recall Willy walking her back up the aisle, and as they disappeared through the door, into the carriage that would convey them to Buckingham Palace, into the eternal partnership they’d pledged, I recall thinking: Goodbye,” he wrote.

Prince Harry also claimed that Prince William and Kate encouraged him to wear his infamous Nazi costume in 2005. Harry was 20 at the time, and the photo of him in a military shirt and red swastika armband holding a drink and a cigarette made headlines across the world.

“I phoned Willy and Kate, asked what they thought. Nazi uniform, they said,” wrote Harry, adding that when he brought the costume home and tried it on, “They both howled. Worse than Willy’s leotard outfit! Way more ridiculous! Which, again, was the point.”

Harry has since expressed deep remorse over the outfit, calling the decision “one of the biggest mistakes of my life” in the Netflix docuseries Harry & Meghan.

Prince Harry tells PEOPLE in an exclusive interview that being known as the “spare” to his older brother throughout his life was challenging.

“For as long as I can remember, I’ve heard and seen the term ‘spare’ to describe me. I knew the only way I could write this book with a good conscience would be if I openly and honestly confronted my experiences and leaned into that which once held me back—including this term,” he says. “While I know much of my life may seem unrelatable, I do think most siblings can relate to struggling with comparisons, and my brother and I are no exception.”

Kate and Prince William have kept a low profile in recent weeks after celebrating the holidays with the royal family. The couple and their three children — Prince George, Princess Charlotte and Prince Louis — joined King Charles, Queen Camilla and other family members on Christmas Day for the royals’ annual church outing.

Prince william kate family royal christmas 2022

Samir Hussein/WireImage Prince William, Prince George, Princess Charlotte, Prince Louis and Kate Middleton

As seen in a video shared on Twitter, Princess Kate opened up about what her morning was like in conversation with the crowd.

Accepting flowers from a little girl named India, Kate asked, “Have you had a nice morning? Has Father Christmas been?” referencing the traditional British name for Santa Claus. India said yes and politely asked the royal if she had enjoyed the day so far as well.

“They got lots of lovely things, thank you very much,” Kate said of her kids’ gifts.