Rachpall Kaur and her son Uppal served the youths, many of whom were wearing school uniform, only to be caught out by their own security camera.
A police probe was launched after a neighbour reported seeing a schoolboy buy a bottle of brown ale. PC Chris Cooke followed up the call and seized the store's CCTV footage.
It showed a string of young males entering the store to purchase alcohol. According to the footage, none were asked for ID.
Both Rachpall and her son pleaded guilty. Rachpall was fined £800, plus £125 costs and a £15 victim surcharge. Her son was fined £200, plus £125 costs and a victim surcharge.