Joan L. Leonas nee McGuire, age 90 of Lincolnshire, passed away peacefully on December 29, 2020. Beloved wife of the late Joseph Leonas. Beloved wife of the late Robert Frenzer. Loving mother of seven children. Adored grandmother of fifteen grandchildren. Great grandmother of eight great-grandchildren. Loving aunt, cousin, and friend to many. Joan was a retired Chicago Public School teacher and a member of the Catholic Church Dominican Third Order. Formerly of Highland Park, Illinois and Elmwood Park, Illinois, Joan graduated from Notre Dame High School in 1948 at the top of her class. Joan graduated from Aquinas College in Grand Rapids, Michigan in 1952. She was an accomplished pianist, an avid bridge player and worked as a bilingual secretary, being fluent in Spanish. Joan enjoyed swimming, tennis, ping pong and trips to the Indiana Dunes. She loved the Art institute of Chicago and the Chicago Symphony. Services private. In lieu of flowers tax deductible donations to the Melissa & Jimmy Boratyn Foundation are greatly appreciated to continue the work of Joan's granddaughter, Melissa Boratyn who passed away from breast cancer in June of 2020.The Foundation address is: 3320 W. Foster Ave. Box 191, Chicago, IL 60625. To leave a condolence or for more information visit www.funerals.pro or call 847.537.6600.