The town's magistrates' court heard on Tuesday that 33-year-old Debbie Campbell, from Redthorn Court , set herself up as a collector for the charity, but instead pocketed donations from April 2012 to July the following year.
And because the donations were anonymous, the amount she stole remains "an unknown amount of money".
Campbell claimed that she was an innocent and that someone had impersonated her after, not one, but two separate consignments of merchandise, including collection boxes, sent to her by Help for Heroes, went missing or were stolen from her car.
However, District Judge Liam McNally saw through Campbell's lies, and tears, and convicted her, telling her that he did not "accept for one moment" that collection boxes were stolen from her car.
He also told her she had aggravated her crimes by "cheating" those who had readily given donations from their hard earned money, which she then used "to line your own pockets".
The District Judge said the reluctant evidence of a local shopkeeper, who told of Campbell, whom he knew, leaving two collection boxes in his store, and emptying them each month, was "truthful", and later "copper-fastened" by the evidence of a policewoman who once challenged her about being a bona-fide charity collector.
The policewoman said that Campbell, who was known to her, initially failed to produce any accreditation, but that later, someone calling herself Campbell, reported to the local station with the proper documentation from the charity.
Campbell initially told her defence lawyer Francis Raffery that she "took a notion" of wanting to be a collector for Help for Heroes, which was set up to aid wounded soldiers and their families, after seeing something about the organisation on the internet.
She later told the court that she had "been inspired" by her former father-in-law, who was a successful collector for the charity.
She claimed that the first consignment sent by the charity never arrived, although they had a delivery record, signed for by a 'K Walters".
Campbell denied knowing anyone of that name, adding that when the charity sent her a second consignment, she put into her car to stop her children getting at it.
Campbell, who claimed she only put one collection box in the shop, and then "totally forgot about it" and never went and emptied it, said the consignment was stolen from the boot of her car when she had left it momentarily unlocked outside a shop.
"I really did want to collect monies for Help for Heroes," said Campbell, but the collection boxes were stolen: "They were away, sure they were stolen out of the car".
She further claimed the police officer had "definitely made a mistake" about speaking to her about being a charity collector.
Campbell said it couldn't have been her as she was miles away staying with her father and had no car to drive to Coleraine. However, she accepted that police did find two collection boxes in her home.
Campbell said her children had taken them from the consignment before she had had a chance of putting them in the boot of her car to stop her children getting at them.
Campbell, who was released on her own bail of £500, was convicted of a total of seven charges including stealing over £200 worth of merchandise from the charity, duping a shopkeeper into allowing her to put collection boxes in his store, and five specimen charges of stealing "an unknown quantity of money from collection boxes belonging to Help for Heroes".