You're welcome Phil, but thanks for posting.

Ref "margaret spelt marguritte, must be latin pronounciation"

at first I thought no, not necessarily. Don't forget this was centuries before schooling and improved literacy/spelling standards became the norm for the general population, even for the scholars such the clergy. As with a great many Parish Records etc, the name is actually spelt logically, just as it's spoken or sounds.

That said, you may be correct wrt "Latin". To me it immediately looked like French, especially the last "te". You probably know this was the "international" language at that time for academics and diplomats. To my surprise I now find that originally French was actually derived from Latin, which until the 1600s had preceded French as the international language. And as I guess you're thinking, many members of the clergy would have been used to seeing and reading old Biblical text and verse written in Latin as per the monastries.

Re the records being patchy, don't forget we're relying on fragile paper records surviving for over 300 years, often stored in damp cold places in large books which were being handled regularly, and also prone to being nibbled by rats and suchlike. Also, I can well-imagine Jarrett being spelt in many ways, perhaps even with a "G", so a tricky one to search. In fact I've just seen some C17th & C18th records on Familysearch for Jarrett in Hampshire, one of the later records was spelt Jeraet !. On the plus side, it's not the most common of names to search, unlike my Jones and Wrights for example, so I think you've done very well indeed to get back that far.