Many thanks for this comment. Again, I had an impression that altho Manx law seen=ms to have been silent on deceased wive's nieces, that Bishop WIlson did adopt a very strong line on all disciplinary issues, which would probably include this, which you have confirmed.
That being the case we have an interesting scenario. If Jane Casement (who died in 1718 was the daughter of Archdeacon Sam Wattleworth, then that presents NO problems.
San W also died in 1718.
In 1719, Wm Casement married Mary Thomason, who was the daughter of the Revd Thomason of Ireland and Esther Wattleworth, who was definitely the daughter of Sam W.
Although Bishop Wilson had a high regard for his friend the late Sam W, I would be surprised given his very strict character, if he would have turned a blind eye, even for his late friend, if the Casement/Thomason marriage infringed what he would regard as the "prohibited degrees". I think he would have said "NO". ALthough it is supposition, this strengthens my own belief that Jane Wattleworth was unlikely to have been Sam's daughter.
The only possible way I can see the marriage slipping by is that Jane was a widow when she married WM Casement in 1708, but as her previous marriage had been in 1702, I would be surprised if anyone in Malew had forgotten her maiden name, and pedigree, so I think it unlikely that Jane could slip beneath the radar.
What about Mary Thomason. Archdeacon Sam's will left something to his granddaughter Mary Thomason, so in 1718-1719 the relationship between Sam and his granddaughter was brought to the attention of the church authorities in written form, so it is hard to believe that they were unaware that she was Sam W's granddaughter ! I do not think she could get below the radar.
My conclusion is that the church authoritiesand Bishop Wilson either approved a marriage that might not have fouled Manx law but fouled the Bishops own stricter rules, and this I find VERY unlikely, or Jane W was NOT a daughter of the Archdeacon.
Surmise I admit, but can anyone see any other explanation