I'm easily confused - are you (+ we) still looking at James Crebbin who married Jane Cowley ? - if so then I can point out that Ann Laborn (later Ann Mosscroft and still later Ann Laborn by which wch name she was buried had an illeg child (who died prev to marr with Wm Mosscroft) and then 2 more illeg children with Wm Craine

One of her children Thomas by Wm Mosscroft disappears from 51 census (as does James Crebbin) before both re-appearing but not together unfortunately - Thos is lodging with Mother and James is very recently married - maybe they were both together in England where Thomas must have trained as a blacksmith.