Many thanks for responding.Since posting, I have learnt a bit more.
Your information poses a question for both of us I think.While I have been given information to indicate my Emma has siblings William, Jessie & Henry (indeed Jessie(y) (sister) was a witness at her wedding).The date of marriage for Jonathan Metters does not agree with information give by another party.This makes me wonder if they are the same family and may require further investigation.The information you referred to on the census does imply possible connnection but unfortunately I cannot help confirm or deny a link. Ain't ancestors wonderful :-D
If you know for certain that the father was called Jonathan and was a tailor then what I can say is that so far I have only come across one Jonathan Metters, who has consistently been listed as a tailor and living in Tavistock. Noted as deaf in later census.That is not to say there isn't another one, just that none have appeared in my searching
Ideally, seeing the 1861 census may help clear up a few questions but unfortunately I don't live in Devon to check it.
If you do think that there may be a link I do have a bit more information (not much) but it may help.