Hello Lee,
Elizabeth Sheafe of whom you speak is also my 10th-great-grandmother. Like you, I too, have been attempting to find the origins of her family. She was the third wife of Valentine Austin.
I have been through extensive records of the Cranbrook group and can find no evidence to support a connection there, except a slim possibility that the mother was Sarah Gyllebrand, the former wife of Harman Sheafe. Harman died young and left behind two known girls bearing similar names to the girls of our mutual Sarah and also born at appropriate times for the Titherton marriages.
However, I have been trying to following the family Edmond Sheafe, who is claimed to be a brother on two of the girls marriage licences as well as one Timothy Sheafe. Although no relation is stated for Timothy Sheafe I would expect that he would have been a brother, uncle or close cousin. I do have some notes on Edmond and Timothy but do not have them at hand as I write this quick reply to your posting.
The Thomas in Elizabeth and Valentine's family is, I believe, named for Valentine Austin's brother, Thomas, in the place of the Thomas born to Valentine's second wife, that Thomas having died as an infant.
It is interesting to note that there is a distinct possibility that another direct Sheafe cousin married into the same Austin line - a descendant of Valentine's son , to wit:
SHEAFE, Caleb married AUSTEN, Mary on 22 Nov 1683, she 20, spinster, do Matthew, maltster, of Wye & Caleb Sheafe, bachelor, 28, of Willesborough Canterbury ML. Caleb had a brother named Edmund, also at Willesborough.
I would be interested in hearing your line of descent from this family. Mine is through Henry Austin and Mary Rigden.
Regards,
Susan