A stony-faced Kate Middleton was photographed for the first time since the release of her rogue brother-in-law Prince Harry’s bombshell memoir — in which he painted the Prince and Princess of Wales as bullies.

Middleton, 41, appeared stern but stoic at the wheel of her black Audi on Wednesday wearing a scarf and a beige coat.

The exiled “Spare” heir left no stone unturned as he made private family squabbles and conversations public.

The Princess of Wales was reportedly “appalled” by the endless claims in the book.

“She is appalled at him for dragging her name through the dirt and is finding it hard to forgive,” a source told US Weekly.

In it, Harry dishes on Middleton’s fractured relationship with his wife, Meghan Markle, 41.

The Duke of Sussex, 38, offered his side of the infamous dress-fitting fallout between the women of Windsor, which he claimed left Markle “sobbing on the floor.”

“Meg asked if Kate was aware of what was going on right now. With her father. Kate said she was well aware, but the dresses. And the wedding is in four days!” Harry wrote in the book.

The rogue royal then stunningly revealed personal text messages sent back and forth between Markle and Middleton amid the disagreement over Princess Charlotte’s bridesmaid dress.

Elsewhere in the protocol-shattering book, Harry recalled a time when Middleton reluctantly lent the “Suits” actress her lip gloss — and was “taken aback” by her request to borrow it.

He claimed the Princess of Wales “grimaced” when Meghan squeezed the gloss onto her finger and applied it to her lips.

Harry has also claimed that stereotyping caused a “bit of a barrier” when his wife met the Prince and Princess of Wales.

“There was a lot of stereotyping that was happening, that I was guilty of as well at the beginning,” he said in a recent interview in the lead-up to “Spare” being released.

When asked to clarify, Harry added, “Well, American actress, divorced, biracial, there’s all different parts to that and what that can mean if you are — like a lot of my family do — if you are reading the press, the British tabloids … there is a tendency where you could end up living in a tabloid bubble than actual reality.”

Middleton was last seen in public stepping out of Sandringham House on Christmas Day to attend the morning service at St Mary Magdalene Church in Norfolk with her husband, Prince William, and their three children.

Harry also made stunning claims about his brother, the heir apparent.

He alleged Prince William, 40, got physical and tossed him to the floor in a bitter fight two months before he and Markle left the royal family.

“I don’t think they were ever expecting me to get — or to become — to get into a relationship with someone like Meghan, who had, you know, a very successful career,” Harry wrote in the memoir.

Harry also claimed that the Prince and Princess of Wales “howled with laughter” when he told them he was thinking of wearing a Nazi costume to a party in 2005.

Buckingham Palace has declined to comment on “Spare,” which was officially released on January 10.