Or this a a red herring, as is the Elizabeth with the Gawnes
Thomas/John Thomas and Ann appear to have been married and in Liverpool in 1841 so maybe they married in England pre-1937 hence the difficulty in finding the marriage.
If Elizabeth and/or Ann had been married before then this makes the task even more difficult.
I suggested to Sue (pers.comm) that perhaps the link lies with Thomas Gawne's mother, Jane Watterson (married John Gawne of Ballafesson in 1797) but maybe that's clutching at straws.

As we haven't heard back from the original poster of the thread we might all be on a wild goose chase but it would be nice to tie this family in to her Edward Watson.

Jane