The office manager from St Helens bought the elegant creation by top London designer Ian Stuart, who featured on Channel 4’s “The Posh Frock Shop” series, specially for the occasion
And it won her a bottle of champagne after wowing the judges on the 1930s Pullman-style Northern Belle train during the journey to the Berkshire racecourse on Thursday.
Jeanine, 54, said: “It was a wonderful surprise – the icing on the cake of a wonderful day out with my husband Nick. We saw the King and Queen arrive in their carriage during the Royal Procession.
“Then we even managed to back a couple of winners on the track as well.”
She had originally planned to buy the “Secret Garden” dress from a designer shop in York for her daughter’s wedding four years ago, but unfortunately they didn’t have her size.
Then she spotted it on the Vinted internet site for pre-loved clothes and, as it came with a fascinator and all the trimmings, reckoned it would be just right for the Ascot trip.
“Even second hand it was still expensive,” she said. “But it was worth every penny. Even at the racecourse, I was getting loads of compliments over it.
“Nick and I last went to Royal Ascot 30 years ago shortly before we got married, so it was lovely to repeat the trip as a 30th anniversary present.
“Doing it in luxury on the Northern Belle with such delicious food was the icing on the cake.”
It was the second time she and Nick had travelled on the Northern Belle, which actor Bill Nighy once described as “the Grand Dame of luxury travel”.
And she is hoping her daughters might take her back for a Mother’s Day lunch trip next year.
The train’s Director of Food and Beverages Brian Clark said: “Jeanine absolutely sparkled, proving that impeccable style and a touch of Ascot magic go hand in hand.
“She looked sensational, bringing elegance, flair, and just the right amount of fabulous to the grandstand.
“But when it comes to a day at the races, everybody is a winner with the Northern Belle.”
The train will be back in the North-West for a trip to Bath next Friday (June 27) from Manchester and Crewe, with an excursion from Liverpool to Edinburgh and the city’s Fringe Festival in August.
Then in September there will be a steam-hauled trip over the picturesque Settle-Carlisle line from Liverpool and Newton-le-Willows.
Fares start at £365. For more details of these and other trips, see www.northernbelle.co.uk