They asked her to explain the horse's improved form compared with his previous run - at Ludlow on 10 December - where he had been beaten in excess of 129 lengths.
The stewards noted the trainer's explanation, but since she had failed to report that Surprise Gunner had been struck into during the Ludlow race they took action over her failure to abide by Jockey Club instruction H14.
Before visiting the stewards, Mrs Jones said: "He got struck into badly and he lost his confidence quite badly. He's a brave little horse."
The Folkestone stewards were also in action after the first race, the Burmarsh Novices' Hurdle, in which the Paul Webber-trained Running Man, an 8-11 favourite, was pulled up.
Webber was unable to shed any light on Running Man's flop and the stewards called for a vet to give the horse an endoscopic examination.
The race was won by Arctic Fancy, who is to be trainer Julian Smyth- Osbourne's first runner at the Cheltenham Festival.
Betting on the Gold Cup at the Festival was shaken up yesterday following news that Cyfor Malta will miss the remainder of the season with a leg injury.
The Martin Pipe-trained six-year-old had been a 10-1 chance in William Hill's list for the Cheltenham showpiece after his victory in the Grade Two Pillar Property Chase at Prestbury Park last month.
A rule change allowed six-year-olds to compete in the Martell Grand National this year and Cyfor Malta, who was given 11st 4lb in the Aintree weights unveiled last week, was a 16-1 shot for the National with Hills.
But Cyfor Malta, winner of the Cathcart Chase at Cheltenham and John Hughes Trophy at Aintree last year, has some heat in a foreleg.
David Johnson, in whose colours Cyfor Malta runs, explained: "If the Gold Cup had been two months or more away, he would probably have been OK, but the vets said it would have been 50-50 if we had kicked on, and as he is only six and his future is ahead of him, I decided it would be fairest to put him away for the season.
"I am absolutely gutted, to say the least, as the news came as a shock to me, as I really did think he would have taken all the beating in the Gold Cup, and I had backed him accordingly.''
Hills later cut Dorans Pride to 8-1 from 9-1 for the Gold Cup and also shortened the Pipe-trained Hanakham from 33-1 to 25-1.
Nicky Henderson said last night that Barna Boy (County Hurdle) and Ebullient Equiname (Stakis Casinos Final) will both represent their owner Lynn Wilson, the Northamptonshire cricket club chairman, at the Festival.
Both go straight to Cheltenham, where Barna Boy will be looking to extend his impressive Festival sequence. The winner of the County Hurdle in 1997, he was fourth in that race last year and was also fourth in the Coral Cup in 1996.
Henderson added: "Barna Boy will have a racecourse gallop, while I was very pleased with Ebullient Equiname's second at Uttoxeter the other day."Reuse content