The John Sweet mentioned in "The Home Lots . . . . " that you referenced was not the first husband of Mary Sweet Holliman - it was her son. Her first husband, whom she had immigrated to American with about 1632, had died in Salem, Massachusetts between 6 Jun 1637 when he last appeared in the Salem records and 25 Dec 1637 when "widow Sweet" received a land grant for a household of four.
Sometime the next year she married Ezekial Holliman who lived at that time in Salem. They most likely married in Salem although no record exists. They were in Providence, Rhode Island in April 1638 when Ezekial Holliman baptised Roger Williams and then Roger Williams in turn baptised the ten or eleven original Providence settlers.