kate middleton
Middleton wore a 2011 Max Mara wrap dress to her appearance Tuesday. Reuters

Kate Middleton visited the Hope House in Clapham, London, on Tuesday; her first public appearance of the year since announcing her pregnancy in late 2012.

The Duchess of Cambridge also showed off her baby bump for the first time publicly. Now four months pregnant, she wore a 2011 Max Mara wrap dress that showed, while she remains slim, her belly is definitely growing.

Middleton greeted dignitaries and posed for photos before visiting with the residents of Hope House, a residential center for women run by Action on Addiction.

In addition to helping addicts get clean, the charity, for which Kate is Patron, also aids the families of addicts and trains professionals to better serve those in recovery. Drug and alcohol addiction as well as other addictions including gambling are treated at the center, which has locations in London, Merseyside and Wiltshire, according to the UK Telegraph.

While Middleton visited with women in an art therapy class, she told one of them, "Well done for getting sober."

Chief Executive of Action on Addiction, Nick Barton praised Middleton on her involvement with the charity.

“I speak of what I know -- somebody who wants to help, is helpful and genuinely interested and is intelligent,” he told the Telegraph.

“I can only speak (of) what I know. I've met her several times and I found her to be engaging, I found her very natural, I found her actually genuinely interested in the subject,” he continued.

“You can tell a lot from people's questions and she asks really good questions. They're not routine stuff; they're questions of someone who wants to learn. I find her very easy to deal with.”

While Kate gears up for many other upcoming events, including announcing three new charities with which she will be involved in March, according to the Daily Mail, many are curious to see how the Duchess will dress her bump.

The news source details that, Middleton has commissioned close friends Natasha Rufus Isaacs and Lavinia Brennan to design maternity to wear for her.

“She’s determined to remain fashionable between now and the birth and doesn’t want to be seen as frumpy,” a friend told the Mail.

In her first public appearance since the announcement of her pregnancy at the UK’s Sports Personality Year Awards in December 2012, Middleton wore a green Alexander McQueen by Sarah Burton gown that concealed her lower stomach, and was referred to as a "maternity dress" by Grazia.

Burton, who designed Middleton’s wedding dress, has also apparently expressed interest in designing her maternity clothes, according to ABC News.