Kate Middleton traded princess duty for mom duty in London Wednesday when she took baby Prince George for a walk — and we have the exclusive pictures! Kate and William's dog Lupo also came along, as the Duchess of Cambridge pushed the future king of England in his stroller. The trio enjoyed the fresh air in Kensington Gardens, which is basically their backyard. Just yesterday we saw the new royal mom decked out in a tiara that once belonged to the Queen Mother. Will and Kate took up official duties on Tuesday, joining the queen for the annual diplomatic reception. But for her time with George, Kate swapped the traditional headpiece for a baseball cap and donned some sneakers, looking like an everyday mom.