« Reply #13 on: Saturday 14 April 18 21:12 BST (UK) »
Mary Michell married David Stephens of St Ives 4 Feb 1743 in Gwinear. So could it be you've mixed 2 Thomas Michells? It's not an uncommon name in the area.

Cornwall: Allen, Bevan, Bosisto, Carnpezzack, Donithorn, Huddy, James, Retallack, Russell, Vincent, Yeoman
Cards: Thomas (Llanbadarn Fawr)
Glam: Bowler, Cram, Galloway, James, Thomas, Watkins
Lincs: Coupland, Cram
Mon: Cram, Gwyn, John, Philpot, Smart, Watkins
Pembs: Edwards (St. Dogmael's)
Yorks: Airey, Bowler, Elliott, Hare, Hewitt, Kellett, Kemp, Stephenson, Tebb