I got a bit carried away down at the Library, but never mind. I only found one Belinda Stevenson in all of 1841,51,61 East Hannay. She was 25 in 1861. which makes her a little old for yours, but ages are a bit random in some of these.
Anyway, here are all the Stevensons I could find in those Census's in East Hannay:
1841 CENSUS - East Hannay, Berkshirep6
William STEVENSON 35 Ag Lab
Mary 30
Eliza 11
John 10
William 9
Jane 7
Oliver 5
Ferdinando 4
Sidney 1
All born in county
p13
Thomas STEVENSON 45 Farmer
Mary 35
Mary 19
All born in country
p15
John STEVENSON 50 Baker
Martha 40
Martha 10
Leddia 8
Elizabeth 6
1851 CENSUS - East Hannay, Berkshire - HO 107/1689Schedule 4
Charles STEVENSON Head Widower76 Pauper(Farmer) Berks, East Hannay
Sch 35
William STEVENSON Head Mar 47 Timber
Carter Berks, East Hannay
Ann Wife Mar 45 Oxon, Ensham
William Son U 18 Timber Carter assists his father Berks, East Hannay
Oliver Son U 16 Plough Boy
Oxon, Ensham Berks East Hannay
Ferdinando Son 14 Berks, East Hannay
Sidney Son 12 " "
Esther Dau 9 " "
Sch 39
James STEVENSON Head Widower 63 Ag Lab
Mary Dau U 28 General Serv
Henry Son U 26 Ag Lab
Eliza Dau U 24 General Serv
Edwin Son 5
Margaret WOOD Lodger Mar 48 Annuitant
Allborn Berks, East Hannay
Sch 82
Charles STEVENSON Head M 40 Ag Lab
Sarah Wife M 33
Edwin Son 12 Scholar
Robert Son 9 "
Mary Ann Dau 6
Thomas Son 3
Ellen Dau 1 month
All born Berks, East Hannay
Sch95
William STEVENSON Head Mar 51 Farmer of 180 acres employing 7 labourers & 2 boys
Eliza Wife Mar 53
Robert Brother U 63 Partners with William
Ann ILES Serv U 19 General Serv Wilts, Upper Hallow
All except Ann born Berks, East Hannay
Sch135
Thomas STEVENSON Head M 61 Corn Dealer Berks, East Hannay
Mary Wife M 57 Berks, Steventon
1861 Berkshire Census - East HannayRG9/736
Sch 107 E. Hannay Village
Thomas STEVENSON Head M 70 Corn Dealer Berks, East Hannay
Mary Wife M 57 Berks, Steventon
Sch 149 Lower End
Charles STEVENSON Head Mar 50 Ag Lab
Sarah Wife Mar 43
Robert Son U 19 Ag Lab
Thomas Son 13 Plough Boy
Ellen Dau 10 Scholar
Thedore(??) R Son 7 Scholar
Sarah Dau 5 Scholar
All born Berks, East Hannay
158 Lower End
Eliza STEVENSON Head Widow 61 Landed Bofesiester(
?) Berks, East Hannay
Harriet GOBLANG(??) Serv U 18 House Servant Berks, Woolston
174 The Green
John STEVENSON Head Mar 71 Grocer Berks, East Hannay
Martha Wife Mar 61 Berks, Childrey
Martha A Dau U 30 Grocer's Dau Berks, East Hannay
Belinda Dau U 25 " " " "
194 Upper End of Village
William STEVENSON Head Mar 54 Cartman Berks, East Hannay
Ann Wife Mar 54 Oxon, Ansham
Charles Father Widower 81 Miller Berks, East HAnnay
William WILKS Serv U 10 Cartman's Lab Berks, Wallingford
199 Upper End of Village
Sarah STEVENSON Head U 40 Laundress(??)
Henry Brother U 38 Groom
Margret WOOD Aunt Widow 56 Former(?) Hoteler(?)
Edw
ardin WOOD Brother-in-law U 15
All born Berks, East Hanny