Ridden by Barry McHugh and trained by North Yorkshire-based handler Ann Duffield, Just Lille romped home by five lengths from Lady Eclair.
Citizenship came home third in front of 2000 spectators at the six-race meeting on Wednesday.
"It was a wonderful night," Helen said. "We love it at Hamilton and have now had four winners there.
"The Silver Bell victory is the biggest win my partner and I have ever had. Some owners never get a winner, but we have been blessed.
"The celebrations afterwards were quite boozy, with a lot of champagne flowing!
"They really look after you in the winners' room at Hamilton."
And Helen revealed that trainer Ann's goat Nutty is a secret weapon in Just Lille's success.
She added: "Just Lille is an extremely sensitive animal.
"She won't go into her horsebox alone for journeys, so Ann always puts Nutty in there too to give her company.
"Just Lille also won't go down to the race start without a lead horse, but this timidness changes as soon as the race starts!
"Another amazing thing about Just Lille is that at two years old she had to get bolts screwed into her left foreleg after splitting the bone while running on the gallops at home.
"She didn't race until she was three but now has 11 wins after making a full recovery."
Also present on the night was trainer Ann, who was thrilled that her horse, priced at 12-1, managed to romp clear of the opposition.
"Just Lille won very impressively," Ann (46) said.
"She had been second in the Silver Bell race the previous year, so it was good to see her go one better.
"Just Lille is seven years old now and she is like a good bottle of wine in that she gets better with age.
"Although my husband George — who rode a lot of winners round Hamilton in his 40-year career — wasn't at the meeting, he was yelling at the telly at home!
"Jockey Barry was brilliant. He has ridden plenty of winners for us.
"He has always been talented and has gained in personal confidence and ability to do the job.
"Just Lille is a good mare and he gave her a great ride."
Ann revealed the high regard in which she holds Hamilton Park Racecourse.
"Hamilton does the best job out of all the tracks in Britain," she said.
"People there make you feel so welcome.
"They are professional and friendly and their track is always in great order.
"Hamilton Park do such a good job that I actually wrote them a letter a few years ago which supported their bid to get the Silver Bell."
For more information on Ann's Sunhill Farm yard in Constable Burton, visit www.annduffield.co.uk