I didnt bother with the marriage as the focus seemed more on Selina's origins - but the witnesses may solve the unreadable mother's name in 1871;-
witnesses; comfort brown and alfred read
1861 census of
Ecton (Wellingborough District) - RG9/Piece: 951 Folio: 18 Page: 18 @ Front Street
Uriah
Jelley* 58 Household Head born Ecton : an Agricultural Labourer
Valley Jelley 39 Wife born Whysmington: a Lace Maker
Comfort Jelley 22 dau
Ecton : a Lacemaker
* Spelled JOLLEY in the 1851 census
Given their ages, Valley is obviously not Comfort's mother - so a 2nd marriage, as Uriah was a Widower in 1851
Marriages Dec 1855 BROWN Sarah Wellingbro 3b 374
CLARK Valley Wellingbro 3b 374
HACKSLEY Henry Wellingbro' 3b 374
JOLLEY Uriah Wellingbro' 3b 374
So, Selina's parents marriage - QED I think
Marriages Jun 1862 Brown George Wellingborough 3b 201
Jolley Comfort Wellingbro 3b 201