I know this is a while back that you posted this but this identification may need further consideration.
Joan Newman (Burges) WIFE OF WILLIAM died 21 July 1624
The parish register only says that the wife (note not widow) of William Newman was buried on that day - it doesn't give her name. Joan would also have been extremely old (in her 90s) at that date and that might (but not always) have merited a comment in the register. I'd be inclined to think that she died much earlier and this is the wife of another William Newman. In fact I think this record might have been the burial of Margaret who was wife of William Newman. He made a will dated 1623, but did not die until April 1625.
Nell