Steve and all,
Before I get into this, I should preface my comments that after doing a lot of digging, I agree with Steve's analysis that there must be two families involved here. I will do this in point form.
1. I show John's wife as Olive Catherine, not Olive Caroline.
Children assigned to this marriage:
2. Lavinia's marriage to Henry Potter declares her parents as John & Olive
6. William A (not H)
8. Judah's marriage to Lavinia (Mains) Campbell list his parents as John & Olive
9. Mary's marriage to Judah W Ells list her parents as John & Caroline
10. James Henry's marriage to Agnes Maria Rogers list his parents as John & Caroline.
11. In the 1881 census for Canning, Olive C Ells, 80 and widowed is living with Judah, 43 and widowed and his 4 children.
12. John Ells, son of Sam'l and Rebecca Amelia died 9 Nov 1868 in Canning.
13. Caroline Ells, widow, married Isaac Bennett on 11 August, 1864. She was living in Aylesford at the time.
Coupling all of this information with Mary's death record (see Steve's note) which states that her parents were Isaac Bennett & Caroline Ells (see point 9) indicates that there were two families; John and Olive C & John and Caroline and that they are not the same people.
I suggest that 2 through 8 are correctly assigned while 9 & 10 belong to John and Caroline.
Now we need to find out who John and Caroline were.
Regards to all