Federal prosecutors said a Wethersfield woman has pleaded guilty for her role in a $1.6 million food stamp fraud scheme. US Attorney David Fein said Tuesday that Lillian Adames pleaded guilty Monday in federal court in Hartford. Fein said that according to court documents and court statements, Adames, 46, illegally exchanged food stamps for cash between October 2006 and March 2009. He said she was helped by her husband and others, exchanging food stamps for cash with customers at six grocery stores in Hartford. The listed store owners were unconnected with the businesses and allowed their names to be used for ownership and licensing purposes.