The young royals have been strong advocates for mental health, setting up the Heads Together campaign in 2016 through their official charity, The Royal Foundation.
She first wore the striking design when she was pictured leaving Berlin for Hamburg as part of the Royal Tour in 2017.
One of the policies up for discussion at the summit is a declaration committing to putting mental health on an equal footing with physical health.
In addition to getting to spend some kid-free time together, William and Kate got to further push their mental health initiative.
Her husband was only delighted to make a joke and said that his wife's handiwork had nearly "ruined the picture" but as you'll see from snaps and videos of the event, she saw the amusing side of his remark. The initiative was started by Dixon Chibanda and teaches the women to become lay health workers.
Hazard still dreams of Real Madrid
The Chelsea player says his dream remains to sign with the Spanish giants and Real Madrid could make a move in January . Eden Hazard continued his sensational start to the season as unbeaten Chelsea inflicted more misery on Southampton .
Its eye-catching lilac colour looks divine on the mum of three, who returned to her royal duties following a six-month maternity leave last Tuesday.
Let's hope Prince George, Princess Charlotte and Prince Louis are all in bed, because mom is out on the town!
The couple, along with Prince Harry, have been credited with helping break down the stigma surrounding mental health by encouraging open conversations about it.
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.