You will find Isabella with her parents at Hawkden, Gamrie, in the 1861 census. They were there in 1851 too. Alexander had a croft of about 37 acres. At the time of the 1841 census the family was at Protstonhill and Alexander was a farm servant.
Isabella Rankin Wood was born in the parish of Gamrie, Banffshire, on 29th March 1860.
I have done a great deal of research on the Rankins in Gamrie as they are amongst my ancestors. Christian was born about 1816, but I don't think, from memory, that there's a record of her baptism. If you get Christian's death certificate and find her parents, let me know and I will probably be able to tell you about her ancestors. The Gamrie Rankins can be traced back with certainty to the beginning of the parish registers in 1704.
Graham.