Britain's Catherine, Duchess of Cambridge receives flowers from children as she leaves Hope House addiction treatment centre after an official visit in London February 19, 2013. REUTERS/Stefan Wermuth (BRITAIN - Tags: ROYALS ENTERTAINMENT)

Britain's Catherine, Duchess of Cambridge leaves Hope House addiction treatment centre after an official visit in London February 19, 2013. REUTERS/Luke MacGregor (BRITAIN - Tags: ROYALS ENTERTAINMENT)

KATE Middleton confessed today that she is nervous about giving birth, as she showed off her baby bump for the first time at a public event.

Kate's admission came as she chatted to a group of women recovering from drink and drug addictions at a treatment centre run by the charity Action On Addiction of which she is patron.

The Duchess spent time with an arts therapy group at Hope House in Clapham, south London, where the centre's clients had completed paintings charting their battle with substance abuse.

Lisa, a mother-of-three who did not want to give her full name, said: "I did ask her if she was nervous (about giving birth). She said it would be unnatural if she wasn't - she's human like us."

The 34--year-old, who turned to drink during a violent marriage which lasted 18 years, said: "I said 'Congratulations and good luck, I hope it all goes OK'."

Kate also chatted to Natalie, who has a two-year-old daughter and is due to give birth to a second child in July - the same month as the Duchess who is more than four months pregnant.

The 28-year-old said the talk also turned to babies when they chatted: "We're due about the same time. She's been unwell and feeling better now and I felt pretty much the same the first time."

The Duchess arrived at the treatment centre, which is based in a large period property in the leafy suburb, and was greeted by dozens of photographers, cameramen and journalists.

Wearing a MaxMara dress, she looked relaxed and tanned after her Caribbean holiday and shook hands with Nick Barton, Action On Addiction's chief executive, before clasping her hands around her small baby bump.

The Duchess made the gesture a number of times during the visit to the centre and seemed completely at ease with her growing figure.

The royal visit was overshadowed by the furore caused by the comments of novelist Hilary Mantel, who has suggested the Duchess is a "shop-window mannequin" with no personality, whose only purpose is to breed.

During a lecture at the British Museum, the double Booker Prize-winner said Kate appeared to have been "gloss-varnished" with a perfect plastic smile in contrast to Diana, Princess of Wales, whom she described as awkward and emotionally incontinent.

She seemed to suggest that the "painfully thin" Duchess was selected for her role because she posed no risk of showing any character.

Prime Minister David Cameron, who is in New Delhi on an official visit to India, defended the Duchess.

Mr Cameron said of Mantel: "I think she writes great books, but I think what she's said about Kate Middleton is completely misguided and completely wrong."

The Prime Minister told the BBC: "What I've seen of Princess Kate at public events, at the Olympics and elsewhere is this is someone who's bright, who's engaging, who's a fantastic ambassador for Britain."

During the visit, Kate was taken to the centre's kitchen and watched as a lunch of chicken and bacon pasta with salad was prepared by some of the clients.

Some of the ingredients for the meal - packs of chicken and bacon and packets of brown pasta - were laid out on a table and Kate asked one of the women who was chopping mushrooms: "Do you like the menus and do you enjoy the cooking side?"

She got the reply: "I find it very therapeutic."

Kate also made the chefs laugh by asking: "Can people get away with being fussy or not - if they don't like mushrooms?"

One of the staff told her the women have a low glycaemic index diet to control blood sugar levels to ensure they do not have highs and lows dictated by their meals.

Kate was making her second visit to the centre. Her first was a private trip she made to learn more about the charity Action on Addiction before becoming its patron.

Hope House provides therapy for the women, who will have gone through a process of detox and are clean of alcohol and drugs but still need support before they are ready to return home.

The women's art therapy session was close to Kate's heart as she has a keen interest in drawing and painting.

The Duchess is also royal patron of a charity called the Art Room, which uses art therapy to help raise the self-esteem and confidence of school children.

Kate sat at the head of the table and around her were seated seven women whose colourful paintings were laid out in front of them.

One client called Natalie, who had drawn a winding road, told Kate: "This is my road to recovery. This is when I was in addiction, my life was in complete darkness and then gets a lot brighter."

The Duchess listened intently to her story and told her at the end: "Well done you for getting sober."

Natalie said afterwards: "I've got to say I'm sober and clean. When I was in the darkness I never thought that would happen."

The 28-year-old relapsed during her first referral to Hope House but was able to get clean and returned and has completed her period of therapy at the centre.

A reception for supporters and senior staff from Action on Addiction was held at Hope House and Kate shared a joke with the son of one of the charity's donators.

Katie Woodward, 45, whose father established a charitable trust which has donated to Action on Addiction, brought her son Hugo, nine, and daughter Serena, seven, to meet Kate.

Hugo was celebrating his birthday today and the Duchess asked him: "Are you doing anything nice today?"

The guests erupted in laughter as Hugo paused before answering, and finally said: "I'm going to a restaurant."

A moving moment came during the reception when the Duchess heard from a woman who received treatment at Hope House and is now forging a career as a playwright.

Sonya Hale, 35, from Congleton, Cheshire, has had an award-winning play produced at London's Royal Court theatre and another will be staged next month at a festival at Southbank Centre.

The writer began using soft drugs aged 14 and progressed to harder substances like heroin and crack and spent much of her 20s in and out of prison after being convicted of petty crimes.

She told the Duchess and guests: "On arriving here just two years ago I was a broken, frightened shell of a woman, who lacked any of the basic skills necessary to live a normal life.

"I've been heavily addicted to drugs and alcohol from an early age, I spent much of life roaming the streets, sleeping in shop doorways and using drugs."

Ms Hale said that after treatment at Hope House, "I felt held, I felt saved, I felt loved for what seemed like the first time ever.

"Through a combination of group work and counselling Hope House nurtured me and supported me to make the changes necessary to turn my life around."

Before leaving, Ms Woodward's two children presented Kate with a posy outside the building as dozens of photographers recorded the moment.

Nick Barton, Action on Addiction's chief executive, praised the Duchess after the visit: "She was wonderful with the clients. They fell in love with her. They opened up to her.

"She's such an easy person that they were talking to her in a very comfortable way, and I think surprised themselves at how easy that she made it for them.

"She seemed in good spirits, in good health, and very comfortable."

Telegraph.co.uk