Hello again,
I know we seem to be bombarding you with all this - sorry.
From my point, and I know that others see it the same way, it is based on the evidence of censuses and certificates.
If you have assumed that Elizabeth Mundy is your key ancestor because of the census and you do not have any other proof, then I would urge you to consider all we have written about here.
Working from your John William's marriage certificate:
* father's name
* occupation of father and John William
* censuses support all these and can then be used further back e.g CF's marriage
Additionally
* Elizabeth's spouse John Wilson can also be verified thro' census
* Elizabeth's daughter, Margaret Ellen lived a long life and can be identified in census etc
Regards
Heywood