Middleton, 25, put on dazzling smile for photographers when she left her parents’ Berkshire home and was driven by her brother James to her London flat on Monday morning.
She later re-emerged carrying a tennis racket, wearing jeans, boots, a white top and dangling earrings – and flashing a smile.
Middleton, who is an accessories buyer at a company called Jigsaw, visited the offices in Kew, London, on Monday afternoon. Some reports in the UK say she was picking up paperwork to work from home this week, while The Mail said she was on “compassionate leave.”
A Jigsaw spokeswoman would not comment, saying, “Kate does work for us. We treat her like any other employee” and would not discuss her personal situation.
The Sun reported that Kate’s boss, Jigsaw owner John Robinson, offered her use of his private villa in the Caribbean, but she decided to stick it out in England.
Meanwhile, army officer Prince William was back at Bovington, where he is based until August.
The couple’s split, after nearly five years together, was confirmed on Saturday.