Kingston Seymour together with several nearby parishes are missing from the Ancestry version of the 1851 census.
From Gordon Beavington's transcription of the 1851 census for KS - see
www.mycensuses.comIs this your family in 1851:
Schedule 61
GRIFFIN Mary Widow/er 40 Farmer 104 Acres Churchill
Samuel 17 Clevedon, Som.
Isabella 15 Clevedon, Som.
Page/Folio 16.417
GRIFFIN Charles 14 Clevedon, Som.
MAY Harriet 26 Dressmaker Bitton, Glos.
TOWNSEND George Servant 26 Ag. Lab Stanton Prior
DENMEAD Eliza Servant 17 Kingston Seymour