There is a long-standing tradition that Thomas Dewey Jr, married his step-sister, Jane Paine, daughter of Thomas Sr's second wife by her first husband.
BUT Anderson disputes this... Great Migration Begins, p 1246:
"Lechford records several documents in which Thomas Mayhew and his wife Jane Mayhew, formerly the wife of Thomas Paine of London, act as guardians for Thomas Paine, Jane's son with her first husband [Lechford 184-86, 240]. Savage introduced confusion by stating that the widow Paine bore the Christian name "Grace" rather than Jane [Savage 3:185]. It may be this confusion that led him to state that the wife of the younger Thomas Mayhew was Jane Paine, allegdly daughter of this non-existent Grace, and therefore his stepsister. Edward Everett Hale Jr., Lechford's editors, showed that Grace did ont exist, and also that, based on the documents in Lechford, there is no evidence that the younger Thomas married a stepsister named Jane Paine [Lechford 184]."
My current concern about this Anderson conclusion is that whether or not Grace existed, couldn't Jane (____) Paine Mayhew have had a daughter named Jane?
We need to find more about children of Jane (_____) Paine Mayhew by her first husband...