actually 16 is very young for marr even at that time (puberty was generally later) and would be noted as 'with consent'
There is a will for a Robert Key marown - I summarised it - ballalough;only son john;wife isabel als oates;made 10 feb 1780 - but couldn't find a matching burial (? if lost at sea but normally this stated in court proceedings)

whoever the isabel key was she had 4 ch at least (all boys) - last in 1794 which make a dob pre 1750 unlikely. The Fick's seemed reluctant to leave wills however