Isabel Key, not sure if this is your person, with many people of the same name. But I have this in my database under 'questions to resolve'

Matthias Quine d 26 Apr 1783/4 Marown [possibly married ealier to Susanna Cowley b 5 Mar 1728 d 1 Jul 1779 Marown]
married Patrick 23 Oct 1781
Isabel Key d 1828
children
Jane Quine b 04 May 1783 Marown

Did Widow Isabel then marry John Bridson?
Isabel Quine or Rey (?Key)d 30 Aug 1828 Peel married John Bridson 06 FEB 1790
Children Catherine b 13 AUG 1791 Patrick