About Salley or Sally (Sarah?) Willey
"Salley" and "Sally" typically are pet names for the given name "Sarah". Given name has also been reported to be Salley Sarah Arnold.
Seeing that her father was born in Leicestershire, and bearing in mind that many amateur genealogists erroneously presume that husbands and wives before the 19th century were born in the same location, it is possible that this Salley/Sally was not born at Mumby, Lincolnshire, England. Further research is warranted.