Hi
here are the full details of the census
Address 1 Ashley Place
Mary is listed as a caretaker and single.
Name: Stamford, Mary A
Age in 1891: 36
Relation: Servant
Gender: Female
Where Born: Royston, Cambridgeshire
Civil parish: St Margaret and St John the Evangelist Westminster
Ecclesiastical parish: St Andrew
County: London
Source information: RG12/83
Registration district: St George Hanover Square
Sub registration district: St Margaret Westminster
ED, institution, or vessel: 9
Folio: 37
Page: 28
I have checked the transcription details against the original image and they are all correct.
and these are the details of Frederick in 1891
Stamford, Adelaide 47 Cambridgeshire Wife St Andrew the Less Cambridgeshire
Stamford, Alfred A 13 Ely, Cambridgeshire Son St Andrew the Less Cambridgeshire
Stamford, Frederick 42 Cambridgeshire Head St Andrew the Less Cambridgeshire
Stamford, Grace Emma 10 Ely, Cambridgeshire Daughter St Andrew the Less Cambridgeshire
Source information: RG12/1285
Registration district: Cambridge
Sub registration district: St Andrew the Less
ED, institution, or vessel: 25
Folio: 104
Page: 7
address 49 Norwich St
occupation marble and stone mason
again I checked against the original image and all details are correct, no specific place of birth for Frederick, just Cambridge.
Hope this helps
Nicky