Hi, Do you have the Full Registration with all the personal information - includes parents names etc - ]
Certificate may be just an extract of basic information taken from the Registration - Good for proof of an event without disclosing personal information to those with no need to know.

Marriage announcements in newspaper - Not everyone posts announcements in the social pages of newspapers.
When they do - there is seldom much personal information
If it is engagement - there may be details about the coming marriage - if marriage - details about the wedding - guests - bridal gown - perhaps honeymoor and where the couple will settle.
Announcemnts in Classified section - may just be that - who, when and where a marriage will take place - perhaps names of parents - perhaps names of witnesses.
What information are you hoping to find ? perhaps there are other resources - that list members can suggest.
Were there children from this marriage ? - or siblings of Margaret Beth?

cheers, Stella