Just posting a follow-up. IF Ruth was Canham, then Joseph and Ann are her grandparents, and John and Hannah are her parents.
Problem: 8 children. On 4 certs Mum is Ruth CANHAM, on the other 4 she is Ruth CANNON! I think, from other information, that the Canham is right, but my cousin insists the Cannon is correct.
I love this job!

Anna