BOURKE/COWLING marriage - 1851/57

[Brentor boy]

I am posting this on the Devon board, but I am unsure where this marriage took place.

Joanna Cowling was born 3 Aug., baptised 4 Sept, 1822, daughter of Robert and Alice. The family lived in Brentor/Lamerton.

In 1851 Joanna is recorded, aged 23, living in Plymouth together with her "sister", Elizabeth, aged 15. I am convinced that Elizabeth was, in fact, her niece.

In August 1857, as Joanna Bourke, widow, aged 39, she married Richard Craig at Plymouth Register Office. Her address is shown as 24, Mount Street, Plymouth and Elizabeth Cowling was a witness.

I am struggling to find any record of her marriage to Mr Bourke between 1851 and 1857, or his subsequent demise. Given that Plymouth was/is a garrison town and a seaport, it is possible that the groom was a soldier/sailor and that any marriage took place elsewhere. The groom's surname also hints at the possibility of an Irish connection.

I would appreciate any information or suggestions that might help me solve this puzzle.