Hi Spanswick,
I am not sure what you have but in 1851 Census Hannah is with her Father Richard born c 1793, Basingstoke.
Her Sons Richard 1838 and Charles 1849 are down as Richards Grandsons
HO107/1681/173/38
Christenings, Basingstoke, Hampshire;
RICHARD Castle, 06 May 1838, Mother HANNAH
CHARLES JOHN Castle, 09 August 1849, Mother HANNAH
(Source Familysearch.Org)
1841 Census in Basingstoke we have;
Richard CASTLE, 45, Labourer
Charles, 10, Labourer
John, 13, Shoemakers Apprentice
HANNAH, 24
RICHARD, 3
All born in County
HO107/385/5/Basingstoke
Christenings Basingstoke, Hampshire to RICHARD/CATHERINE Castle and Variants of Surname;
MARY ANN, 21 Aug 1814
ANNA Castle, 25 Oct 1816***
HARRIET Castel, 26 Oct 1819
CHARLES Castel, 01 Aug 1822
RICHARD Castell, 16 Oct 1825
JOHN Castel, 08 June 1828
(Source Familysearch.Org)
***So ANNA is probably Hannah and Charles/John/Hannah and her Son Richard are at Home with Richard Castle Snr in the 1841 Census.
I cant find CHARLES c 1831's Christening.
This may be Richards Marriage;
Richard CASTLE
Katherine WILKINS
29 January 1814, Basingstoke, Hampshire
(Source IGI Extracted)
CATHERINE Castle was Buried 28 March 1837, Basingstoke
(F/S.Org)
So that is why she doesnt appear 1841 Census
Trish

EDIT;
ALFRED Castle c 1842 from 1851 census seems to be the Illeg Son of HARRIET c 1819;
CHARLES ALFRED Castle Christened 15 Aug 1841, Basingstoke,
Mother HARRIET Castle