I know of a Nancy Blake, née Leach, who at one point lived in Somerset County, Maryland.
She was born in the 1810's (probably in Maryland) and married Hezekiah Blake in the 1830's. They had a daughter named Rachel Ann.
In the 1860's was living with Samuel French, Mary S Blake, Thomas J Blake, Daniel P Blake, George J Blake, and Robert Fountain in Potato Neck, Maryland.
She died in Maryland in 1880. I don't know her ethnicity. Not sure if it's the same person but there's some overlap.
I am trying very hard to find out more about her because she is as far back as I have gotten in my family tree.