Pignatelli was born in New Jersey and lived in Nashua, New Hampshire. She received her associate degree from Vermont Junior College and her bachelor's degree from University of Denver. Pignatelli also went to Northeastern University. Pignatelli worked for the Nashua Public Housing Authority as director of tenant services and as executive director for the Nashua Girl's Club. Pignatelli served in the New Hampshire House of Representatives from 1986 to 1992 and was a Democrat. She then served in the New Hampshire Senate from 1992 to 2002. Pignatelli served in the New Hampshire Executive Council from 2004 to 2010 and from 2012 to 2014.