Hi,
Found this family on the 1871 and 1891 census.
Civil parish Sandness
address Norby
Betty Sinclair age 33 born Walls
Grace Sinclair daughter age 1 born Sandness
James Sinclair son age 8 born Sandness
Jamima Sinclair daugther age 5 born Sandness
John Sinclair age 35 born Sandness occ crofter
July Sinclair dau age 7 born Sandness
Laurence Sinclair son age 3 born Sandness
1891 census
civil parish Walls, Sandness, Papa Stour and Foula
address 1 Norby
Elizabeth Sinclair wife age 53
Grace Sinclair dau age 21
James son age 8
Jemima Sinclair dau age 25
John Sinclair head age age 55 occ crofter
Lawrence Sinclair son age 23 occ seaman
Phillis Sinclair dau age 14
James is down as a scholar age age 8, so James on the 1871 census may have died, but unable to view original census to see if there are any transcriptions errors.
Julie