Just looked at the FreeCEN site which gives the King Edward census for 1851. The Davidsons are at Sunnyside where William (38, native of Turriff), is farmer of 13 acres. Jane (26, a native of Forgue), his wife, Alexander, William, Isabella and Jane, his children. Also there is Barbara "Jaws" - obviously Tawse mistranscribed - William's mother (60, a native of Turriff). Barbara is described as a former housekeeper. With any luck Barbara will still be alive in 1855 and you'll find a death certificate with more detail.
According to James Godsman's book on King Edward:
"In 1850, William Davidson and Jane Barclay, daughter of Alexander Barclay, North Mains of Craigston, assumed the tenancy. They had sons John, George, Peter and James, and a daughter Jane. In 1860, George Gerrie leased the holding for 21 years."
Godsman does sometimes get things wrong, so don't accept everything in the above passage without checking for yourself.
Graham.