There were two main Johnston families in Rousay. One was descended from a John Johnston born in 1811, and the other from David Johnston who belonged to the same generation. It is known that John's parents were Charles Johnston and Janet Harrold who also had a son called David born 11 November 1813 but it has not been established that he was the David Johnston who went on to marry Jean Gibson.
David married Jean Gibson on 2 November 1835 and they had three children, Bella, Margaret, and John. This John married Ann Sabiston and became a farmer at Testaquoy on the small island of Wyre. A descendant of his, Jim Johnston, still farms at Testaquoy. Other descendants include John Johnston, Isobel Irvine, Hugh Johnston, Struan Johnston, and Alice Johnston. David must have died young for Jean remarried in 1843 to a Gilbert Craigie.
John Johnston was born on 15 July 1811 and died in 1896. He married Elizabeth Reid, a daughter of the centenarian George Reid. They lived at Kirkha' in Rousay and raised a large family there. Descendants include Anita Thomson, Jim Marwick, Jimmy Craigie, Hugh Marwick, and Beth Johnson.