The Fry family, from Bo’ness, claimed the cash from the draw made on 18 May.
Peter Fry, 90, and wife Mary, 86, along with their three daughters, Margaret, 64, Janet, 59, and Isobel, 57, play as a syndicate, putting on five lines twice a week.
The win comes six years after Peter’s cousin Annette Brown, 82, became the UK’s 2,500th National Lottery millionaire after a £1.151.496 million Lotto jackpot triumph.
Incredibly, Margaret Fry is also enjoying her second big lottery win after scooping £20,000 on the Lotto Millionaire raffle in 2015.
Commenting on the latest win, Margaret said: “My dad went down to Tesco on Saturday as normal and passed his tickets over to get checked.
“The till operator advised him that he had won a ‘wee bit of money’ and it was too much to pay out in the store - thinking it was around £500, he had no idea we were about to become millionaires.
“After arriving home and telling my mum, they both phoned me. The first thing I did was go straight over to their house as I knew it could be big.
“We called Camelot together and after confirming all the details, they asked if we knew how much it was worth.
“When we were told £1 million we were in such shock - my mum kept saying ‘a million?’ in such disbelief. It was the most amazing feeling!
“As a family we’ve always played the game but never really believed we would win a substantial amount, this shows it could be anyone - it’s truly life-changing.”
Peter and Mary, who are retired, have six grandchildren and five great-grandchildren, with another on the way.
Margaret added: “I think the best thing about this for us is that we can take care of the family.
“My mum and dad will be able to buy their house and make changes which will help my mum who struggles to get about.
“I think my sisters and I need to let it all sink in a bit more before we even start thinking about what we’re going to buy.”
Peter bought the family’s ticket from Tesco on Links Road, Bo’ness. Their winning code from the Lotto Raffle draw on Wednesday 18 May was NAVY 1281 6617.
Speaking of the family’s latest win, cousin Annette said: “I’m so happy for Peter – it couldn’t have happened to a better man and talk about keeping it in the family.
“Winning The National Lottery made my life so much easier and I hope it’s the same for him. I can’t wait to see him and celebrate our luck together.”
Last September David and Carol Martin, both 54, from Hawick in the Borders, won half of the UK’s biggest-ever Lotto jackpot a staggering £33m.
Glasgow’s “G” postcode has the most high tier lottery wins (over £50,000) across Scotland according to data from National Lottery operators, Camelot. Aberdeen was second. Scotland’s biggest city also came in at number four for high tier wins across the whole of the UK.