It was bothering me as to the maiden name of the mother of your Ann BROWN. Think I have shown that it was PROUD. (edit - the clincher is the census mentions of Angerton as the place of birth)
Summing up what is known about Margaret the mother of Ann BROWN. To find her maiden name we need to find birth certificate for her daughter Ann BROWN born c. of her marriage to Jonathan BROWN between 1861 and 1871 or her marriage to Thomas ROBSON 1881 to 1891.
What is below I made up from what is known in chronological order and then filled in the extra bits I found (also in chronological order) - which all now seem to add up.
From census records Margaret was born c. 1840 in NBL at Haltwhistle or "Angleton" (wherever "Angleton is and if it is transcribed right)
Either of these might be the Margaret PROUD who married Jonathan BROWN in Gateshead District in 1864 (if indeed that marriage is relevant):
Births Apr-Jun 1841
Proud Margaret Haltwhistle 25 260
Births Jul-Sep 1841
Proud Margaret Haltwhistle 25 265
This will be the 1841 census for the Margaret PROUD whose birth was registered in Q2 of 1841
1841 census Ho107-839-16 folio 16
Angerton, Blekinsopp, Haltwhistle
William PROUD 30+ Coal Miner Y
Ann do 30 Y
Jane do 9 U
Henry do 5 Y
Ann do 2 Y
Margaret do 2 month Y
(ages over 15 may be round down to the nearest 5. The "y" means borth in this county)
(My 1934 Gazetteer says "Blenkinsopp , par. and Ham., with collieries, S. Northumberland, 3 m. W. of Haltwhistle; 2488 ac., pop. 549." )
1851 census shows the other Margaret PROUD was age 9 living in Featherstone with parents Henry and Isabella.
This is the one we want:
1851 census Ho107-2389 folio 414
Lead Gate, Ivestone. DUR
William PROUD Head Mar 45 Miner NBL
Ann do Wife Mar 41 NBL
Jane do Daur Unm 19 NBL
Henry do Son Unm 14 Miner NBL
Margaret do Daur 10 Scholar NBL
Matilda do Daur 7 Home NBL
Hannah do Daur 7 Home NBL
Matthew do Son 4 Home FUR Lead Gate
1861 Jonathan BROWN is not married so he marries a Margaret between April 1861 and March 1871 in CUL, NBL or DUR.
This is almost certain to be Margaret in 1861
1861 census Rg09-3807 folio 65
Church Chase, Whickham, DUR
Joseph SHAW Head Mar 48 Shoe Maker YKS Whitby
Mary do Wife Mar 49 DUR S. Shields
Margaret PROUD Servant Unm 19 House Servant NBL Greenhead.
(Greenhead is just West of Blenkinsopp)
Freebmd marriages of a Jonathan BROWN to a Margaret between 1861 and 1871:
(note that this may not have been the first marriage of either of them)
Marriages Jan-Mar 1864
Brown Jonathan Gateshead 10a 717
Proud Margaret Gateshead 10a 717
(At this time the Gateshead District covered Whickham where Jonathan and Margaret were living in 1871. No sign of this marriage in DRO but there coverage is no where near complete.
Marriages Jul-Sep 1869
Asquith Margaret Skipton 9a 58
Brown Jonathan Skipton 9a 58
GILL James Skipton 9a 58
SMITH Mary Jane Skipton 9a 58
(This location is less likely to be the one we want)
1871 census Rg10-5063 folio 23
48 Wagon Way Row, Marley Hill, Whickham, DUR
Johnathan BROWN Head Mar 32 Coal Miner CUL Alston
Margaret do Wife Mar 30 DUR Haltwhistle
David McQUEEN Boarder Unm 30 Coal Miner Ireland
1871 baptism of Ann BROWN
Baptisms, Lanchester District - Record Number: 733037.0
Church: Primitive Methodist Circuit
26 Dec 1871 Ann Brown, of High Row, Marley Hill, Whickham, born 20-Dec, child of Jonathan (coal miner) & Margaret Brown
1881 census Rg11-5024 folio 4
Marley Hill Hole. Marley, Whickham, DUR
William ROBSON Head Widr 68 Coal Miner NBL Berwick?
John ROBSON Grandson Unm 23 Coal Miner DUR Marley Hill
Margaret BROWN Servant Mar 39 Domestic Servant NBL Angleton?
Annie BROWN Servant Unm 9 Scholar DUR Marley Hill
(Where is the husband of Margaret and what is her relationship if any to William ROBSON (age 68 born in NBL Berwick?) the head of the household. What is this place which might read Angleton?)
1891 census shows Margaret has married a Thomas ROBSON. Presumably between 1881 and 1891 though maybe they were just living together.
By 1901 Margret has died.
1901 census RG13-4831 folio 104
Salisbury Street, Morpeth Castle, NBL
Richard FERGUSON Head Mar 28 Railway Platelayer NBL Morpeth
Ann do Wife Mar 29 DUR Marley Hill
Jane do Daur 2 mo NBL Morpeth
Thomas ROBSON F in Law Widower 50 Coal Miner Hewer DUR Hebburn on Tyne
Amber, for your family scrapbook you may want to get some of the certificates related to your ancestors.
BMD certificates cost £9.25 from here (you can pay more and wait longer by getting them through a third party)http://www.gro.gov.uk/gro/content/certificates/