Kate Middleton Steps Out, 'Nervous' About Birth

Kate Middleton has officially debuted her baby bump in London on Tuesday, just over one week after images taken of her on vacation were released.

The first official engagement since the vacation in Mustique included the Duchess of Cambridge visiting staff members at Hope House, a residential center that aids recovering addicts. The occasion marked the first time the 4-and-a-half months pregnant Middleton revealed a small baby bump.

The Duchess, 31, donned a black and white MaxMara Studio wrap-dress paired with black heels, according to the Daily Mail. The loose-fitting long-sleeved dress barely revealed the mother-to-be's growing shape.

Action on Addiction is one of five charities of which the Duchess is a patron, and the royal met with women at Hope House who are recovering and congratulated them on their way to recovery.

During the outing, Middleton admitted her anxiety over the imminent arrival of her first child.

"I did ask her if she was nervous [about giving birth,]" one onlooker told the U.K.'s Mirror. "She said it would be unnatural if she wasn't- she's human like us."

Meanwhile, Middleton was photographed while on vacation on the private Caribbean island with her husband, Prince William, and other members of her family earlier this month. The images were published in three countries, infuriating St. James's Palace.

"We are disappointed that photographs of the Duke and Duchess on a private holiday look likely to be published overseas," a spokesman for the couple at St. James's Palace told People magazine. "That is a clear breach of the couple's right to privacy."

Adding to the controversial bikini pictures, Middleton suffered another blow earlier this week after a bestselling author called her a "plastic princess made for breeding."

Hilary Mantel, a double Booker Prize winner, released the harsh comments about the Duchess of Cambridge that also included criticism over weight.

According to the author, Prince William's wife is "painfully thin as anyone could wish, without quirks, without oddities, without the risk of the emergence of character." Her explosive speech has drawn fire in the U.K., and the full version will be published in the London Review of Books, scheduled for released Feb. 21.

Prime Minister David Cameron defended Middleton, saying that while Martel was a "great writer," her words about the Duchess were "hurtful" and "misguided," according to 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," said Britain's Prime Minister.