Her mother’s name was Elizabeth and her father was not present at marriage so could have been either abroad (unlikely) or deceased.
_____________

In 1871 she was widowed and living in Durham at The College with one unmarried duaghter:

Name Relation Condition Sex Age Birth Year Occupation  Where born
THORP, Mary Head F 72 1799 Yorkshire
THORP, Mary E G Daughter F 47 1824 Northumberland
SPOOR, Hannah Servant F 31 1840 Northumberland
ROBSON, Mary Servant F 25 1846 County Durham
DETCHON, George Servant M 78 1793 Northumberland

Ref: RG10 Piece: 4966 Folio: 15 Page: 24

Registration District: Durham
Civil Parish: The College
Municipal Borough: Durham
Address: The College, The College, Durham
County: Durham
________________

This looks like the early death of her maiden daughter:

Surname First name(s) Age District Vol Page

Deaths Jun 1885   (>99%)
Thorp Mary Elizabeth G 61 Durham 10a 204
________________

And this has to be her death, albeit a bit older than in the censuses:

Surname First name(s) Age District Vol Page
Deaths Mar 1880   (>99%)
Thorp Mary 84 Durham 10a 211
________________

Their marriage from Family Search, 2 different records (Possibly two of Marriage Licence, Parish Register and Bishop’s Transcripts):

(A) Marriage Bonds and Allegations for the Diocese of York:

spouse: Mary Robinson
other: Elizabeth Robinson
Name: Charles (Reverend) Thorp
Spouse's Name Mary Robinson
Event Date 06 Oct 1817
Event Place York, England
Spouse's Mother's Name Elizabeth Robinson
Indexing Project (Batch) Number I03867-7
System Origin England-EASy
GS Film number 1470325

AND:

)B) Bishop's transcripts for Little Ouseburn, 1666-1864
spouse: Mary Robinson
Name : Charles Thorp
Spouse's Name Mary Robinson
Event Date 07 Oct 1817
Event Place Little Ouseburn,York,England
Spouse's Previous Husband's Name
Indexing Project (Batch) Number M01840-4
System Origin England-ODM
GS Film number 991084
_______________