The information that I have comes from a Jenks Family Genealogy written in the 1930s:Jonathon Jenckes Jr. b. 1718, Cumberland, RI; m. 1736; d 1787 Winchester, N.H.His spouse was Hannah or Harriet Pullen.
In response to your information:My source says that Jonathon and Hannah had ten children born between 1737 and 1755. An internet source says that Jonathon died in 1755.
If your information is correct, Jonathon would have married Hannah Rasor, who as the widow of Jonathon Jenckes married William Pullen.
Obviously, there is much research yet to be done, but thanks so much for your clues.