The brand has been worn by the likes of Dame Helen Mirren and Gwyneth Paltrow.
Lisou was founded in 2018 by Rene MacDonald. The ethical brand plants five trees for every item bought.
It also has been donating 20 percent of profits to the COVID-19 Support Fund.
Kate and William have been attending a number of events in a safe manner amid the pandemic.
They recently visited the launch of the Hold Still campaign at Waterloo Station today, where she wore a wintery coat. The Hold Still campaign was launched in May, in which the Duchess invited Britons to submit their lockdown photography.
Fans of the Duchess and stylist pandemic dressing can buy the masks from website Amaia.
Kate’s pink mask, the Adult Reusable cotton face mask in Pink Pepper, costs just £15.
The brand states there is a high demand on masks so allow three weeks for orders to be fulfilled.
You can buy Kate’s Betty Blue Rainbow Print Lisou shirt here.
How did Kate Middleton become a royal?
Kate Middleton, or Catherine, Duchess of Cambridge, was born on 9 January 1982 at the Royal Berkshire Hospital, Reading, England.
She was born to Michael and Carole Middleton, a former flight dispatcher and air hostess. The couple founded a party supplies company, Party Pieces, in 1987 – now estimated to be worth £30 million.
Kate has a younger sister Pippa Matthews, 34, and a younger brother James Middleton, 31.
Kate and her family moved to Amman, Jordan, in 1984, where the future Duchess was educated at an English-speaking nursery school.
After moving back to Berkshire the family sent Kate to private school, St Andrews School. She went on to briefly study at Downe House before moving onto Marlborough College where she boarded.
For university the young Kate attended the University of St Andrews in Fife, Scotland. Here she was awarded an undergraduate MA (2:1 Hons) in history of art.
Relationship with Prince William
Kate met Prince William when they were both studying at St Andrews, and both living in St Salvator’s Hall. Famously, William reportedly took a fancy to Kate after she wore a see-through dress during a fashion show.
In 2003 the couple began dating and lived together during their second year of university.
The couple split in April 2007, however, in October they were back together.
Prince William proposed to Kate Middleton with his late mother Princess Diana’s engagement ring in October 2010. The couple were holidaying in Kenya at the time.
On 29 April 2011 they married at Westminster Abbey with a whopping 26 million watching the event live.
Kate wore an Alexander McQueen dress worth a reported £250,000 on the big day.
Kate assumed the title “Her Royal Highness The Duchess of Cambridge” and also became the Duchess of Cambridge on the day.