I’d agree with Richard that the birth cert for Jane Boswell could well be worth getting hold of.
I’m tantalised by the references to the names Mordecai, Jane and Sarah, the surnames Boswell and Wainwright and to the fact that Jane is a travelling musician, as it all seems to point to a connection
somehow to a family I’ve been looking at.
I’m interested in Elijah Boswell, born c.1796 (who did have several wives on the go at the same time

), and who had a cousin Mordecai Boswell (born I believe in Misterton, Notts, in 1820 so not the son of Phoenix listed here). This Mordecai used the alias Wainwright, and was a travelling musician. From the JGLS:
… In the churchyard there ' Sarah Delarena Wainwright Boswell, a Gypsey child 6 weeks old who died under Windmill Hill,' was buried on December 17, 1849. She was, I fancy, a daughter of Mordecai Boswell the well-known fiddler, as he used the alias Wainwright, had sisters named Sarah and Deloreni, and was at that time and later generally about Doncaster and Retford, which were also favourite haunts of his cousin Elijah ….... Mordecai Boswell born 1820 was the son of Absolom and Mary Boswell. There is another baptism to this couple of a daughter, Jane Matilda, at Wormesley, Yorkshire, in 1818.
I’ve got a Phoenix Smith and a Phoenix Charlotte in my tree; their names also get written as ‘Fenwick’ quite often.