Their marriage record is found in Warwick Marriages 1850 - 1882, Vol. 1. According to the entry, Peacy was 20 years old, and William was 42. It was his third marriage.
Miller family: Will Hambly Miller and wife Emma, Aunt Peace and husband Will, son Arthur, daughter Vira and her husband Earl Dodge, c1908?
Notes
In the Federal Census of 1870, William F. & Phebe A. Miller, ages 32 & 26, are living at Coventry, RI. They have two children: Henrietta 2 and Mattie 1 month.
In the 1880 Federal Census the family is at Coventry with William's mother, age 81, and two daughters by one of William's earlier marriages: Martha, age 10, and Grace B., age 6.