Hiya Bruce
Thanks for your help. In response to your earlier post, in the 1841 she appears as Debra Casady age 40, in Liverpool, ref HO107/557/3. She states there that she was born "in same County" ie Lancashire. In the 1861 however where she appears as Debora Cassiay in Liverpool, she states Isle of Man as her place of birth. She gives her age as 70, by the way.
Her marriage record from 1826 gives her status as "Spinster", so I'm confident that she was born Corlett. Also, her son Michael's birth certificate states her "maiden surname" as Corlatt.
Best wishes, Bill