"I don't like it out on show, as soon as someone comes into the house," she says. "That's my past. People here know me as Alison - Greir, Logan and Fraser's mum. Yes, I swam, but it's not a huge deal.
"My life has changed and sometimes it's hard to think back. It's nine years since I retired. In some respects it seems like yesterday, but so much has happened in my life - it's totally different now. Sometimes it feels like it happened to another person."
The couple broke the mould for Scottish swimming with 50 metres freestyle gold 12 years ago. It was the first swim title won by a Scot since David Wilkie in 1974 and first by a woman since Elenor Gordon in 1948.
The Milngavie and Bearsden AC swimmer had been in the sport for more than 20 years. She had won Commonwealth silver in 1998 and reached the 2000 Olympic final but performances seemed to have struck a plateau until her Canadian husband bucked the established wisdom of high-volume aerobic training. Marathon runners do high mileage in athletics but sprinters do not, he observed back then, questioning the logic of sprinters like his wife doing 7000-metre sessions in the pool, as was then the norm.
They focused more on land drills, gym work and 25-metre sprint sets. Suddenly, Sheppard ranked among the world's best. She set a Commonwealth record in the 50m freestyle in 2002 and took bronze at 50m butterfly. This late flowering also included 100m individual medley gold and 50m short-course silver at the European Championships, then the World Cup title at 50m freestyle. The last of these carried a £30,000 prize. She won a fifth successive Olympic selection for Athens in 2004 (the first woman to do so) before retiring.
Although Sheppard set a Scottish 40-44 masters record last year - faster than her 35-39 record - she rarely swims now. Yet tomorrow she will be in Helensburgh where eight-year-old Grier is competing for her old club in the mini league.
She is a busy mum, looking after Grier, Logan and Fraser, while running the Sheppard Swim School and Phoenix Aquatics (the club she and Gary founded) from their home. "It's very rewarding bringing up three boys. It can be very tiring at times but I made them, so I'd better deal with it."
The business uses pools at Bannockburn and Wallace high schools, Tulliallan, Castlebrae, Glenalmond and St Andrews. The Phoenix club is based in Dollar with a satellite club at Glenalmond.
"I don't do any coaching or teaching, just the admin," she says. "Gary coaches and we have instructors and coaches working for us. I love swimming and I'd rather work for myself than nine to five, because I have flexibility. Our office is at home, so if I need to do something I can do it and then come back to it when the kids are in bed.
"Our club is a development programme with a lot of youngsters going through. We want to teach them our way. Once the lesson programme is finished, we wanted it to be us guiding them into competitive swimming, rather than have them go to one of the other clubs we have no control over."
Gary has had one-to-one input with several of Scotland's 2014 team, but not recently. Given his dramatic influence on Alison, is his expertise not used by Scottish swimming?
"I'm pretty sure not very much," she says. "We don't really have a lot of contact any more. Coaches change quite regularly. New coaches have been doing some of the stuff we do. People I used to swim with, who maybe became coaches, started to change their clubs' philosophy and adapt training to different groups of swimmers, rather than just have a generic programme.
"I don't want to put anyone down. I think they just have their set ways. Gary is not Scottish, he's not British and is not one to conform to what one person thinks. He is very much an individual and has own opinions about how people should train.
"Maybe that does not sit well with the higher powers. We are happy doing our own thing. We can see the results and how well the swimmers in our lesson programme are doing."
Sheppard will commentate for the host broadcaster in Glasgow. "Lucky, because we got no swimming tickets. Now I will see every single race."
She struggled with withdrawal symptoms on retirement. "It was a way of life. All I knew was swimming. But I am totally over that now and enjoy the commentary. I have done it for FINA [the sport's governing body] at world championships and it's nice to keep up to date.
"And I'm enjoying watching the boys' progress, becoming competitive swimmers. Grier is certainly talented and Logan is a very good wee gymnast. Who knows where it will go? We don't want to put pressure on them, but they know how good mummy and daddy were at swimming."
The aquatics squad for 2014 is the largest Scotland has had, despite demanding standards. In 1998, swimming and athletics won just a single medal each. Swimming has won nine golds since, athletics none. Can Sheppard account for this?
"I think maybe the talent pool is bigger. People are able to train more, without having to worry about working, and universities are very understanding of training needs.
"I think that people have more opportunities to train at a higher level and that training methods have evolved in the pool. When Gary and I adapted training specifically for my event, it was frowned upon. I was told I did not swim enough metres, but we stuck to our guns and it certainly paid off. Only a handful of others did it."
The over-riding image of Sheppard in 2002 is of her shaking uncontrollably on the blocks unable to adjust her goggles. "Everyone thought it was nerves but I put that down to the adrenaline," she said. "It looked really bad, but thinking back, I was fairly confident that if I didn't fall in and get disqualified, I was going to win. I'd broken the Commonwealth record in the heats and I was a body-length ahead, so that gave me more confidence."