A fight involving youngsters who had been drinking on the estate near Frankmarsh Stores in Barnstaple raised the question of how they had got their hands on the alcohol.
"I have a good relationship with the police and the local authorities and they know that we are not selling to under-18s," said Lesley. "But we saw evidence over the Christmas break that adults, including parents, are buying alcohol on behalf of children."
Adults who purchase alcoholic drinks with the intention of passing them on to those underage can face fines, but Lesley added that the police were reluctant to put resources into prosecutions which can be difficult to prove.
"We told the police that we would make CCTV footage available, along with epos data as proof of purchase, and that these could form the basis of evidence for a prosecution," she told Convenience Store.
Lesley has also written to her MP. "We've got to get the message across that this is an offence which carries a penalty," she said. "I've invited local MPs to a meeting with retailers in the area to discuss this problem."