Duchess Kate made a quick change from mingling with world leaders Tuesday to wearing boots and jeans Wednesday to help ring in the holiday season with kids.

The Duchess of Cambridge, a mom of three, joined kids at a Christmas tree farm outside of London to help them pick out trees to take back to their preschools and kindergartens.

Kate, decked out in a red puffer coat and green sweater, also helped the kids make Christmas decorations and eco-friendly reindeer food and send their letters to Santa Claus, according to Kensington Palace.

PHOTO: Children gather to help Britain's Kate the Duchess of Cambridge to pick a Christmas Tree, as she takes part in Christmas activities in Buckinghamshire, England, Dec. 4, 2019.
onathan Brady/PA via AP
Children gather to help Britain's Kate the Duchess of Cambridge to pick a Christmas Tree, as she takes part in Christmas activities with families and children who are supported by the Family Action charity, during a visit to Peterley Manor Farm in Buckinghamshire, England, Dec. 4, 2019.
PHOTO: Catherine, Duchess of Cambridge hands out reindeer food to children during a visit to Peterley Manor Farm on Dec. 4, 2019 in Great Missenden, England.
Wpa Pool/Getty Images
Catherine, Duchess of Cambridge hands out reindeer food to children during a visit to Peterley Manor Farm where she took part in Christmas activities with families and children who are supported by the Family Action charity in Buckinghamshire on Dec. 4, 2019 in Great Missenden, England.

In one photo from the day, the Duchess of Cambridge was photobombed by an eager child as they made decorations together.

PHOTO: Catherine, Duchess of Cambridge, takes part in Christmas activities with families and children who are supported by the Family Action charity, during a visit to the Peterley Manor Farm in Buckinghamshire, Britain, Dec. 4, 2019.
Jonathan Brady/PA Wire/Pool via Reuters
Catherine, Duchess of Cambridge, takes part in Christmas activities with families and children who are supported by the Family Action charity, during a visit to the Peterley Manor Farm in Buckinghamshire, Britain, Dec. 4, 2019.
PHOTO: Britain's Catherine, Duchess of Cambridge reacts in the 'Elf workshop' during a visit to Peterley Manor Farm where she took part in activities with families who are supported by the Family Action charity, in Buckinghamshire, England, Dec. 4, 2019.
Jonathan Brady/PA Wire via AP
Britain's Catherine, Duchess of Cambridge reacts in the 'Elf workshop' during a visit to Peterley Manor Farm where she took part in activities with families who are supported by the Family Action charity, in Buckinghamshire, England, Dec. 4, 2019.

Kate's visit with kids at the "Elves Enchanted Forest" in Buckinghamshire was in support of Family Action, a U.K.-based charity that provides "practical, emotional and financial support to those who are experiencing poverty, disadvantage and social isolation," according to its website.

Kate, 37, was announced on Wednesday as the charity's royal patron, a role she is taking over from Queen Elizabeth II, who was patron of Family Action for 66 years.

PHOTO: Catherine, Duchess of Cambridge, takes part in Christmas activities with families and children who are supported by the Family Action charity, during a visit to the Peterley Manor Farm in Buckinghamshire, Britain, Dec. 4, 2019.
Jonathan Brady/PA Wire/Pool via Reuters
Catherine, Duchess of Cambridge, takes part in Christmas activities with families and children who are supported by the Family Action charity, during a visit to the Peterley Manor Farm in Buckinghamshire, Britain, Dec. 4, 2019.

Kate's support of the charity continues her focus on families and children, especially the early years of childhood. Just last month, Kate spent two days in the maternity ward of Kingston Hospital Maternity Unit in London to gain working experience.

The Duchess of Cambridge's festive Christmas outing with Family Action is also the latest sign she is fully in the holiday spirit.

PHOTO: Britain's Catherine, Duchess of Cambridge moves a Christmas tree during a visit to Peterley Manor Farm where she took part in activities with families who are supported by the Family Action charity, in Buckinghamshire, England, Dec. 4, 2019.
Jonathan Brady/PA Wire via AP
Britain's Catherine, Duchess of Cambridge moves a Christmas tree during a visit to Peterley Manor Farm where she took part in activities with families who are supported by the Family Action charity, in Buckinghamshire, England, Dec. 4, 2019.

Kate joined her husband Prince William to film a holiday special with British cooking legend Mary Berry slated to air on Dec. 16 at 8:30 p.m. on BBC One.

Kate and William were photographed wearing aprons alongside Berry, a former judge on "The Great British Bake Off."