I wonder if Thomas was an uncle ? - there are two ch Thomas Clague + Ellen Cowin - they are with I think the gparents Thos Cowin + Isabella quilliam in 41, as is the Elizth Cowin who I think is the aunt to John Fell
seems a somewhat complex family - re Sue's point if John Fell/Fayle was illeg he would need find employment (no fam farm) + the mines were the rapidly growing industry with reasonable wages esp for young men - I don't have 1871 census maybe that might give a little more info - also I can't find Eleanor Quinney (? married)