Have you ordered the marriage cert? Who were the witnesses? Any Smith siblings?
And, ignoring her reported age -- is it possible the Kavanaugh marriage was her 2nd marriage? I don't see this couple in Cheshire in 1881 .... ?
1871
Name: Elizabeth Smith
Age: 27
Estimated Birth Year: abt 1844
Relation: Wife
Spouse's Name: Isaac Smith
Gender: Female
Where born: Ireland
Civil parish: Birkenhead
Ecclesiastical parish: St James
Town: Birkenhead
County/Island: Cheshire
Country: England
Registration district: Birkenhead
Sub-registration district: Birkenhead
ED, institution, or vessel: 30
Household schedule number: 90
Piece: 3749
Folio: 67
Page Number: 18
Household Members:
Name Age
Isaac Smith 28
Elizabeth Smith 27
Another possibility:
Name: Elizabeth Smith
Age: 21
Estimated Birth Year: abt 1850
Relation: Daughter
Mother's Name: Catharine Smith
Gender: Female
Where born: Ireland
Civil parish: Cheadle Bulkeley
Ecclesiastical parish: St Matthew
Town: Edgeley
County/Island: Cheshire
Country: England
Registration district: Stockport
Sub-registration district: Stockport First
ED, institution, or vessel: 25
Household schedule number: 42
Piece: 3662
Folio: 122
Page Number: 10
Household Members:
Name Age
Catharine Smith 50
Thomas Smith 26
John Smith 24
Henry Smith 21
James Smith 8
Fanny Smith 28
Elizabeth Smith 21
*****Catherine Smith 17
Margret Ellen Smith 14
Mary Charlott Smith 12