On my family tree I have John Walker, born 1794 in Heage, Derbyshire, died January 1876 in Belper. He married Ruth Waterfall 1796-1852 on 6th July 1817 in Duffield, Derbyshire.
On my tree for his parents, I just had Peter Walker and Martha. But somebody else has her as Martha Pybus, and has a picture (of her?). This is so far back that I can't find any information at all about either of them.
I am fairly certain I have the information on John Walker and Ruth Waterfall correctly, but going back one generation the information just falls away.