The Duchess of Cambridge paid a visit to the borough this morning to meet women recovering from addiction.
She was welcomed by staff at Hope House treatment centre in Rectory Grove, Clapham, her first public appearance displaying a baby bump.
The Duchess became a patron of Action of Addiction in January 2012 and met with women currently being treated.
She took part in an art therapy group, observed a food preparation session and learned about nutrition during the treatment process.
Nick Barton, chief executive of Action on Addiction, said: "The Duchess’ support, in throwing a spotlight on addiction and recovery and helping us to break down the stigma associated with this complex condition, is enormously important.
"We are grateful for her continued involvement with the charity, and her enthusiasm for understanding more about our clients and staff."
Sonya Hale, a former client, said: "The Duchess is lovely and made me feel totally at ease.
"We spoke about how important places like Hope House are in helping women change their lives for the better."
Kate, who is four months pregnant, wore a MaxMara dress and clasped her baby bump before heading inside Hope House.
Her visit comes after author Hilary Mantel criticised the Duchess for being "painfully thin" and said she was selected to be princess because she has no character.