Prince William returned to public duty this week as he met with emergency responders and the people they have helped. However, Kate, the Duchess of Cambridge's absence from the celebration at Dockhead Fire Station raised eyebrows, since it has been "two months since they both appeared in public at an engagement". 7News Europe bureau chief Hugh Whitfeld said that the Duchess of Cambridge delayed her return to work to spend a day with George and Charlotte on their return to school.

       He said that many observers were "wondering where the Duchess was" when William returned to duties after the Cambridges enjoyed a long summer break.

       Mr Whitfeld told Sunrise: "William did have a summer glow when he visited a fire station in south London - without Kate though.

       "It's been two months since they both appeared in public at an engagement at Wimbledon.

       "We haven't seen either of them since then."

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       He continued: "They have been on their summer holidays.

       "We know they took their three children to the Isles of Scilly off the end of Cornwall.

       "I'm told that there is not too much to worry about.

       "George and Charlotte are back to school for the first time since the last school year, so that's probably the best explanation for the absence."

       Kate was understood to be making the most of her children's last few days of the holidays.

       On Wednesday, Prince Louis returned to Willcocks Nursery School after the nursery reopened its doors to pupils.

       The three-year-old royal has been attending Willcocks since he was enrolled in April.

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       On Thursday, Prince George and Princess Charlotte returned to Thomas's Battersea School in south London.

       George will start Year 4, while Charlotte is moving up to Year 2.

       The family of five spent most of their summer break in Norfolk, according to sources, where Kate was spotted by locals teaching her children how to sail.

       It was also reported they spent the last week of August in Scotland with the Queen, who has been staying at her Balmoral residence since late July.