Sir Humphrey Davy - any relation?

[adeledc]

I was always told by my Cornish grandmother (Olive Weight nee Davy) daughter of James E Davy and Emily S Ball that we were related to Sir Humphrey. As he himself had no children, this link (if there is one) must come from siblings above his family tree line.

Olive’s grandparents were Henry Davy 1844 and Emma Doidge 1846
Her great grandparents were John Davey 1806 and Catherine Rowe 1805
Her great great grandparents were John Davy 1778 and Sarah Tregloyne 1783

Any help gratefully received