DeeAnne,
Thank you for your response. Your mother came to the same conclusion that I have. The Winthrop records that I have found do not list a husband for Mary Winthrop, but then I am still waiting to have 3 books on the Winthrop's arrive via Interlibrary loan. If they have any info, I will post it here. At the moment, I believe that James Clark b. 1608 in London, arrived on the Hector in 1637 in Boston and moved to New Haven in 1638 may well be Mercy's father. I have Mercy born in 1644 in New Haven - but none of this is 'writ' in stone!
I welcome any and all corrections and any help!
Sharon