Shannon has worked as a canonist for the Diocese of Portland since 2008. She serves the Department of Canonical Services and Tribunal as a judge, advocate, defender of the bond, and promotor of justice. Shannon is the Director of the Office of Conciliation, which handles disputes regarding decisions made by priests or the bishop. Shannon is also the Coordinator for Deliverance Ministry. In this office Shannon assists parties seeking the services of the diocesan exorcist or have other concerns related to the paranormal or demonic. She also works in various roles for dioceses and archdioceses across the United States and serves the Canon Law Society of America on the Laity Committee.
 
Shannon was raised in South Berwick, ME and currently lives in Saco, ME, with her husband Jack, who is a blues/rock guitarist, and their seven children.