'The christening for yet another sister, Agnes, has not been found in any of the parishes that have been searched. However, Agnes's burial occurred 2 September 1629 at St. Michael, Long Stratton, Norfolk [citing St. Michael, Long Stratton Parish Register]. Agnes may have died at or shortly after birth. Since the names of Agnes and Ann were interchangeable before 1700 in parish registers, it's also possible that Agnes and Ann were one and the same person. Mary's mother, Grace (_____) Bridgham was buried on 18 February 1628 in Morningthorpe, Norfolk [citing Morningthorpe Parish register].'
The fact that Grace (the mother) died in Feb 1628 indicates that Agnes could not have died shortly after birth. Therefore, it is assumed that the Agnes who was buried Sep 1629 was the same person as the Ann who was christened Jul 1626.