Elizabeth Norgin, daughter of William & Jane Norgin was baptised at Biggleswade on 11 May 1783. Was she the Elizabeth Norgin who married Richard Franklin in Biggleswade in 1809 (Richard was of Hatfield Herts), and was her putative father William Norgin the William who married Elizabeth Cooper née Mantle in 1810? If so, and if Jane Franklin was the daughter of Richard and Elizabeth (Norgin) Franklin, then Elizabeth Mantle would have been the step grandmother of Jane.
A lot of ifs but it would explain how the Elizabeth Marsom who made the will was connected to Jane (Franklin) Phipps, and why Jane was described as granddaughter in 1851.
Did Jane Norgin, wife of William, die prior to 1810, and if so was her age at burial given?*
David
*Jane Norgin, wife of William Norgin, postboy, was buried at Biggleswade on 23 Apr 1803.
There's also the burial of John Cooper, wheelwright, at Biggleswade on 8 Jan 1809
Of course, even if this speculation can be proved to be correct, it still doesn't help in tracing Elizabeth Hine!