Michael, who has worked for the supermarket group for 15 years, recently cut back to working just two days a week so that he could concentrate on looking after the couple's four-year- old daughter. Not only has he had to put his career second to his wife's, he has to put up with lots of ribbing from his colleagues about having inside knowledge on what is going on at Sainsbury's.
However, his dedication is paying dividends for his wife's career. Earlier this week Dino Adriano, chief executive of Sainsbury's, picked out Homebase as a potential bright spot in the dreadful saga that is unfolding at the group. Mr Adriano helped found Homebase, and his successor running the DIY operation, David Bremner, recently stepped up to the role of managing director of the group with the brief of turning round its fortunes. The inevitable gossip at Sainsbury's is that Ms Swann will follow this well-trodden path to the group board, making her the youngest-ever executive director and, after Rosemary Thorne, the outgoing finance director, the first woman.
Ms Swann doesn't dismiss the idea. "You have to ask Dino," she laughs, with a disarming openness. "It would go against some of the preconceptions that people have. I've not been here all my life; I'm not in my fifties and I'm not a man. It proves you can have a high-flying career at Sains- bury's and be a bit different."
Indeed, Ms Swann is a relative newcomer at Sainsbury's. She was recruited just over two years ago as marketing director of Homebase, having held a similar position at the Dixons subsidiary Curry's. Her relatively brief career had taken her from a management degree at the University of Bradford via the Tesco management trainee scheme to first Dalgety and then Coca- Cola. A Curry's colleague remembers her as "good, but tense". Her time at Homebase appears to have made her more relaxed. While at Curry's she was behind the decision to open the electrical retailer's largest-ever store, at Junction 9 on the M6. The success of the megastore has driven Ms Swann to embark on a new strategy for Homebase: the opening of two giant 100,000 sq ft stores, the latest being in the shadow of the Millennium Dome at Greenwich.
The logic behind this flight to size is a change in the DIY market. Partially due to the influence of television shows such as Changing Rooms, the average customer at a DIY store is now looking to alter the look of their house, not merely buy a few screws and a pot of emulsion.
Ms Swann has introduced curtains, bed linen, crockery and even furniture into the Homebase stores. So is the intention to steal some ground from Ikea? "Not directly," says Ms Swann. "The market leader in this sector is John Lewis, and it is a fragmented market. We only have to take a bit off a lot of players to build quite a nice market share."
At the same time Homebase is getting about pounds 7m a year to develop ecommerce. Ms Swann argues that only certain parts of the market can really benefit from an online offering - notably power tools, hardware and some of the garden products which Homebase is famous for - while customers are far from being ready to buy curtains, upholstery or even paint over the internet. "In furniture and textiles there is a desire to touch and feel the goods," she says.
The opportunities for Homebase are also beyond the UK. David Bremner predicted at Sainsbury's results presentation on Tuesday that there would be consolidation in the European DIY market. Ms Swann points out that while the UK has just three players dominating the market, Germany has five.
The strains of being a working mother mean that she leaves home at six to drive to the Homebase headquarters in Surrey, so she can leave in time to read a bedtime story to her daughter. Running a DIY chain means that she cannot escape work even at the weekends.
"Last Sunday I dragged my husband and my father to the new Greenwich store," she says. "They ended up spending pounds 300."