Slattery attended a World Conference on Aging in Vienna, Austria, in 1983. One year later she was one of one hundred chosen as a United States Ambassador to make the initial visit to Russia. She served four years as assistant state director of the American Association of Retired Persons before being appointed state director of AARP in 1989.
Slattery served three years as the state coordinator of the Retired Teachers Association, president of the CARNEGIE-STOUT PUBLIC LIBRARY Board from 1984 to 1986, and served on three medical missions with Dubuque doctors and nurses.
In 1988 Slattery spent two months in Quito, Ecuador, where she assisted at the Working Boys Center and introduced a mini special education program. Her volunteer work with such a mission in Haiti was the subject of a 1990 article in the TELEGRAPH HERALD. She has served as a volunteer at the Mercy Health Center, FINLEY HOSPITAL (THE), STONEHILL CARE CENTER, Dubuque Leisure Services, Nativity parish, and the Carnegie-Stout Public Library.