SFHG give the following baptisms including Marys:
13 Dec 1818 George s/o William & Amelia, labourer
1 Jun 1823 John s/o William & Amelia, farmer
21 Aug 1825 Stephen s/o William & Emily, labourer
6 Jun 1828 Mary d/o William & Mildred, farmer
12 Sep 1830 Thomas s/o William & Amelia, farmer
The four year gap between marriage and George's baptism and the five year gap between George and John makes me wonder if William and Amelia had other children baptised in another parish.
1851 census lists Amelia as being borne at Horne, Surrey living at East Grinstread with William, now a brewer, and son Thomas.
In 1861 she's an inmate at Sackville College, East Grinstead, described as carpenter's wife, born Horne, Surrey.
Labourer to farmer easy to understand and brewer as many such did the odd bit of brewing as a side line but jump to carpenter bit strange unless she was covering up his occupation.