Thank you so much, Brian! I've just been to the I of M for a short holiday and sorted it all out, thanks to your lead! Kezia was the illegitimate daughter of Ellen/Eleanor Walkington, who subsequently served Thomas Cashin with an afiliation order in the Peel Ecclesiastical courts (successfully). Interestingly, he had just married his 2nd wife, 6 days before this order! I wonder what she thought! Then, after her death, 8 years later, he married Kezia's mother!

So, I'm afraid that this shows that the Census Enumerator did make a mistake, confusing his(I suppose that it must have been a 'he') Wattersons with his Walkingtons! I am so pleased to have found this all out at last. Many thanks, Jo Swadkin