The Princess of Wales looked delighted today as she arrived at the National Portrait Gallery hand-in-hand with a school girl after arriving by bus. Kate Middleton, 43, arrived to launch an 'interactive trail' to support social and emotional development in under fives at the London Gallery. The Princess was last to get off the bus, and was dressed in in a brown blazer over a black high-necked wool jumper, black trousers and heels, with her hair loose.

She held the hand of one excited little girl and smiled at well-wishers as she walked into the gallery. The Princess joined a group of four and five-year-old schoolchildren drawing self-portraits as part of a new project from The Royal Foundation Centre for Early Childhood aimed at supporting youngsters in the development of crucial social and emotional skills. Kate and children from All Souls CE Primary School in Marylebone then spend time exploring how faces can express feelings and emotions.

The princess accompanied them as they drew themselves - an exercise introduced to encourage them to think about themselves and share their stories. Today's engagement came as Kate's Centre for Early Childhood launched a new initiative, the Shaping Us Framework, in conjunction with the National Portrait Gallery, which the Princess has been Patron of since 2011. Kate Middleton, 43, arrived to launch an 'interactive trail' to support social and emotional development in under fives at the London Gallery.

She held the hand of one excited little girl and smiled at well-wishers as she walked into the gallery. Kate and children from All Souls CE Primary School in Marylebone then spend time exploring how faces can express feelings and emotions. Writing in its foreword, the princess said its aim was to 'create a physically and mentally healthier society'. 'That means taking a profound look at ourselves and our own behaviours, emotions and feelings, ' she added.

The school children will be the first pupils to take part in The Bobeam Tree Trail, which will see them journey through the gallery using portraits as the basis for a range of activities that enable them to use and develop different social and emotional skills. The trail is based on a magical tree, which has grown inside the National Portrait Gallery. All that is known about this rare and unusual tree, which has beautiful, colourful leaves, is that it thrives when surrounded by stories.

The children were asked to help the Bobeam Tree by taking part in activities around the Gallery to discover the stories of people through portraits - listening to audio recordings, using props, exploring facial expressions and finally, by thinking about their own lives, feelings and thoughts while creating a self-portrait. At the end of the trail, children received the choice of whether to 'feed' their portrait to the tree, so it can grow big and strong.

The trail will run from February 4 to March 16 and is completely free to take part in. The school children will be the first pupils to take part in The Bobeam Tree Trail, which will see them journey through the gallery using portraits as the basis for a range of activities that enable them to use and develop different social and emotional skills. Other galleries and museums, from Plymouth to Sheffield, will also be taking part in the initiative.

The princess' latest visit comes on the back of three engagements she conducted last week, attending a Holocaust Memorial Day event in London and visiting a hospice and textile factory in South Wales. Sources are, however, at pains to warn that her recent public duties are very much part of a 'gradual, phased return to work ' following the major abdominal surgery and cancer treatment she underwent last year.

'Some weeks you might see her more, others less,' the source said. As a result, today's visit will be Kate's only engagement his week. The source stressed that for the next few months the princess would replicate a similar pace, undertaking intermittent engagements around her continued recovery which, along with her family, remain her absolute priority. The source added: 'However having conducted a highly personal visit to the Royal Marsden and spent time at two fantastic organisations in Wales, the Princess is excited to be shining a light on the importance of early childhood and the work of the Centre.'.

The visit to the National Portrait Gallery comes a day after Kensington Palace released an adorable photograph of the princess ahead of World Cancer Day on Tuesday. Kensington Palace released an adorable photograph of the princess ahead of World Cancer Day on Tuesday, taken by her youngest child, Prince Louis. Kate appears to be passing the reins down to her children, as her youngest child Prince Louis turned royal photographer.