As Dave said, there are some in Dorset, this is more in line with your date, but no Ann:
1851
Emmanuel Riggs
Born abt 1807 Boghampton, Dorset
Civil Parish: Tyneham
County: Dorset
RD: Wareham
Sub-RD: Swanage
ED: 3
HO107; Piece: 1856; Folio: 238; Page: 2
Emmanuel Riggs 44
Eliza Riggs 42
Selina Riggs 21
William Guy 46
Caroline Steger 28
Sarah Cooper 18
Geoff