Thank you so much Jean. You have been so kind to give me all this information. Yes, it is possibly worth checking out. this link, although I worry that the age in the 1841 census is 23, not 27, which it should be compared to 3 census ages when married to Lister which seem very consistent. Clark is such a widespread surname.
I am extremely grateful for your reply and the interesting information you so kindly supplied. I'm asking a cousin who has been researching this for far longer than me what he thinks.

All good wishes,

Joanne