Thanks for all the replies.
There is a good chance that the Mary Ann Rule buried 1897 is the correct person.
I have found her son, also called John

,living in Camborne in the 1901 and 1911 censuses.
In 1901 John is living with his wife Grace and his sister Susan in Carnarthan Street,Camborne.
He is with his wife Grace and son, also called John

, in 1911.