Kate, the new Princess of Wales, seen for the first time since Queen's death

A sombre Kate Middleton has been seen for first time since the death of the Queen.

Dressed in the customary black colour of mourning, the new Princess of Wales wore large sunglasses as she drove through Windsor.

She was on her way to pick up Prince George, nine, Princess Charlotte, seven, and Prince Louis, four, from school, reports suggest.

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Kate did not join her husband Prince William and the other members of the royal family, who rushed to Scotland to be by the Queen's bedside before she ultimately passed away at the age of 96.

Instead of making the journey north to the Balmoral Castle, the mum stayed behind at Adelaide Cottage.

She remained there to be with the couple's three children, as they started their first day of school.

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Despite initial reports that both Prince Harry and Meghan Markle had travelled to Scotland in order to be with the Queen, it was later clarified that only Harry made this particular trip, though he arrived too late to see his grandmother before she died.

This meant both Kate and Meghan were not present with the British royals in Scotland.

It comes as William and Kate's new titles were confirmed by King Charles III in his first speech as monarch on Friday (Saturday morning AEST).

His Majesty confirmed his eldest son, now the heir-apparent, would take on his former title as Prince of Wales and the Duchess of Cambridge would take on Princess Diana's former title.

"As my heir, William now assumes the Scottish titles which have meant so much to me," the King said.