Kate Middleton
Britain's Catherine, Duchess of Cambridge, smiles as she tours the base of Emirates Team New Zealand, for the America's Cup World Series, at the Royal Naval Dockyard in Portsmouth, Britain July 26, 2015. REUTERS/Luke MacGregor

Kate Middleton, the Duchess of Cambridge is set to return to her royal duties as soon as next week, after a four-month maternity break following the birth of Princes Charlotte in May.

The Daily Mail said the Duchess, 33, will kick off the start of her public duties with a visit to the Anna Freud Centre in London, which is part of a series of appointments aimed at focusing on mental health issues in children and young adults.

According to palace sources, the paper said that the Duchess intends to focus much of her public work in this area in the coming months.

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Kate Middleton set to resume royal duties after giving birth to Prince Charlotte. Stefan Wermuth/Reuters

She is also expected to join Prince William and brother-in-law Prince Harry at the opening ceremony of the Rugby World Cup at Twickenham on 18 September.

Joint engagements with Prince William are also on the cards, including visits to Dundee and North Wales in late October and late November respectively, the paper said.

According to royal aides, William has "settled in well" in his new job as a pilot with the East Anglian Air Ambulance service and has enjoyed the time spent with his growing family at Anmer Hall, their newly renovated Norfolk mansion in recent weeks, the newspaper added.