Kate has a long-standing preference for carrying clutches, or else nothing at all, which helps to discourage people from reaching for her hand to shake.
However, proving that even princesses have off-days, we have to say we're not too sure about her latest attire.
Tuesday's summit focused on political figures, leading academics and policy-makers from around the world coming together with the common goal of better mental health for all.
It was a busy night for the royals, with William and his brother Prince Harry also attending a reception at St James' Palace in London to officially open the International Wildlife Trade Conference. Countries are hoping to come together to fight the stigma associated with mental health.
Kate will meet the curators who have worked on the project before unveiling a plaque to mark the centre's official opening. The initiative was started by Dixon Chibanda and teaches the women to become lay health workers.
The royal donned a chic lilac Emilia Wickstead dress, which she teamed with a pair of pointed nude stilettos and a matching handbag.
This was Catherine's second engagement following her return to work, having taken taking maternity leave after the birth of the couple's third child, Prince Louis, in April. He has since been joined by wife Meghan Markle at mental health charity events.
The couple is also preparing for another big event on Friday when William's cousin, Princess Eugenie, celebrates her Royal Wedding to fiance, Jack Brooksbank, at Windsor Castle.