From 1841 census:
Reference HO107, Piece 757, Book/Folio 20/4, Page 3
Tibenham, Norfolk
Brewster, Henry M 30 Farmer
Brewster, Mary F 25
Brewster, Walter M 4 all born in county.
Don't forget the following, re 1841 census:
1. Ages of adults were (supposed!) to be rounded down to a multiple of 5 years (So Henry could have been as old as 34?!)
2. No relationships (to Head of Household) were mentioned.
3. No place of birth was noted. Just born in county (yes or no), or Scottish, Irish or Foreign.
In 1851, Walter is a scholar at school in Bracondale, Norwich (HO107, 1814, 334, 7).