John Bronson, son of Roger Bronson and Mary Underwood, born Lamarsh, Essex, England in 1602, married Frances Hills in November 1626 in Halstead, Essex. There is a wonderful website created by Cambridge University that has transcribed and indexed six centuries of the parish, manorial, priory and court records of the small town in Essex where these Bronsons emigrated from – Earls Colne in Essex. http://linux02.lib.cam.ac.uk/earlscolne/intro/index.htm

There you can find the baptismal (and burial) records of the children of John Bronson and Frances Hills who were born in England:
Mary Oct 1627, John Feb 1629 – Jan 1631, John Dec 1631 – Mar 1632, Dorcas Dec 1633.

The family emigrated to North America in 1634/35 with John’s brother Richard and sister Mary.

I haven’t tried to trace the Sarah Ventriss/John Bronson information, but I don’t know of another Dorcus Bronson that would have been of the right age for that marriage.