I wondering if anyone can play Devil's Advocate here and dispove my theories before I buy certificates please?:

Fact 1 Catherine Dillon born 1/9/1818 Liverpool (father Patrick).
Fact 2 Catherine Dillon married Thomas Gray 8/11/1838 Prestwich - emigrated
Fact 3 Thomas Gray died 11/11/1856 Sydney, NSW

Theory 1: Catherine Gray married Michael Doyle 1857 Parramatta, NSW
Theory 2: Catherine Doyle died 1869 Sydney, NSW aged 50.