With Prince William deployed at the Falkland Islands, Kate Middleton has revealed that she will spend Valentine's Day with children at a medical facility run by Action and Addiction, one of her chosen charities.

The Duchess of Cambridge is back from her family holiday on the Caribbean isle of Mustique, and continues to sport her chic style as she braces the cold winter. Spotted on London's King's Road on Monday, the Duchess wore a brown leather jacket with a fur rim, knee boots and dark jeans. She accessorized her outfit with a $1,300 Polly Push lock bag by Mulberry, according to sawfnews.com.

Middleton is expected to stay in London while Prince William is deployed to the Falkland Islands for the next six weeks. He will serve as a pilot for the Royal Air Force's search and rescue helicopters. During this time, Middleton will focus on the charities she has chosen to work with.

In January, the Duchess selected a number of charities that deal with a range of issues from drug addiction to helping young people. She has also become a royal patron of East Anglia's Children's Hospices, Action on Addiction, the National Portrait Gallery and the Art Room.

The Duchess has chosen to support organizations that complement the charitable work already undertaken by her husband, St. James's Palace said in a statement.

Middleton has also become a volunteer for the Scout Association, an organization she is well acquainted with. As a girl she was in the junior Scouts wing--the Brownies--where she carried out community service and won several award badges for skills obtained during the process.

Meanwhile, the Duchess has new distractions during her husband's absence. The royal couple recently adopted a black cocker spaniel and Middleton has been spotted taking him for a walk.

A royal rep told E! News that the puppy is only a few months old and comes from a litter known to the couple through a family connection. The puppy's name is yet to be revealed.