The 39-year-old was investigated after reports that shingle was taken from the beach near The Dip, Felixstowe, to decorate her garden.
Suffolk Coastal District Council was informed a “relatively significant” quantity of pebbles, believed to be about six sackloads, was taken.
Police said there had been two occasions when three adults and a child went to the beach and loaded their car with pebbles.
Officers tracked the woman down using the car’s registration number and gave her advice that taking shingle from the beach was illegal.
Paul Patterson, senior coastal engineer for Suffolk Coastal and Waveney District Council’s coastal management team, said: “The removal of pebbles, shingle or sand from Suffolk’s beaches is unacceptable because it may contribute to erosion of the shoreline or increase the risk of flooding.
“Where there is evidence of this occurring the council will take action against those responsible.”