We may be able to find the maiden name of Jane Irvin ...
siblings of Thomas - also baptised at St Michaels ,Workington ,Cumberland
father Thomas / mother Jane
Elizabeth Irvin 25th june 1809
Richard Irvin 11th dec 1814
John Irvin 11th aug 1816
Jane Irvin 7th may 1819
Thomas Irvin 7th may 1819...both the same day...........so - between 1809 - 1814 is 5 years ..maybe Jane and was born between 1809 and 1814 but not baptised - so was baptised with Thomas ...or were they Twins..?
17th May 1807 Thomas Irving to Jane Brown in Camerton,Cumberland might be the parents marriage ?? I will see how close Workington is to Camerton
https://familysearch.org/pal:/MM9.1.1/NXKF-VW5ADDED....That marriage of Thomas Irvin to Jane Brown now looks likely ....Camerton is 3 miles north of Workington ...good news