Hi haylingozzy,
I am descended though Mary Osborne, John Nankivell Osborne's (JNO) sister I believe. In the IGI (her christening) her mother is Peggy Osbourn, rather than Margaret, and has no father listed. JNO is a witness at her wedding in 1837 where her father is given as John Nankivell. I believe that JNO married Jane Drabe in 1829 and I think she is found widowed in Calstock in 1861 with children Betsey, James, Henery and Mary. This is the same town that his sister Mary moved to. Am I on the right track?