Might be worth checking baptisms for a Susanna in Kingsteignton, which is where she says she was born on 1851 census. I found sUsanna with surnames Cornelius, Gillard, Kemp and Pearce all baptised about the right time, in Kingsteignton. from there it would be possible to search for a Susanna Cornelius marriage, and so on.
John Ley could be John Reed Ley son of Nicholas and Jane baptised 20.4.1787 Exeter
Hope this helps.