I am assuming this marriage in Arnold's "Vital Record of Rhode Island" applies to this Levi, because he is identified as "Levi, of Nicholas." They were married by Samuel Wall, Justice. The Rhode Island Cemetery Database confirms these birth dates, and that they are both buried in West Greenwich Historical Cemetery #21.
I am making an assumption that "Nicholas Whitford, of Levi" as shown in the marriage record belongs in this family group. The gravestones of Nicholas & Martha are with the other family members.