Hi everyone,
After multiple hours of research (again!), I have come to the following conclusion for your consideration:
James Bragg's 1670 will lists wife Elizabeth and children James, Elizabeth, and Anne.
James Bragg also left an inheritance for James Barnes, son of Thomas Barnes. James Bragg doesn't tell us in the will what his relationship is to Thomas Barnes.
Thomas Barnes' 1683 will names wife Diana (unknown), and children John, James, and Ann.
Diana Unknown became Diana Bragg in a corrupt tree which is copied in almost every internet genealogy website.
If Diana Unknown had actually been Diana Bragg, James's Bragg's will would have identifed James Barnes as his grandson. He probably would have also left an inheritance for James' older brother, John, as well. John and James were born in 1666 and 1668, respectively. Their sister Anne was born in 1670, the year the will was written.
As usual with corrupt trees, there is possibly a nugget of truth. James Bragg may have been leaving an inheritance to James Barnes, b:1652, son of Thomas Barnes b:1624 and Diana Bragg b:1628.