Theriault, Roselis E. (Hertling), of Somerville, December 31st, 2018. Beloved wife of the late Joseph A. Theriault. Devoted mother of Ronald Theriault, his wife Debra of North Conway, NH and Michael Theriault of Cambridge. Also survived by 2 loving grandchildren and 7 loving great grandchildren. Sister in law of Arilda Theriault and Joanne Theriault, both of Cambridge. All services will be private.