Does anyone know if there was a particular legal process in the years 1841 to 1858 for adoption in Scotland or where I would go to search for records of adoption.

I am looking for adoption papers for Lady Leith Bucanan of Ross Priory, Scotland and Jean Mcnicol (adopted) in the location of Dunbarton, Scotland. They lived at the estate of Ross Priory in Dunbarton, Scotland.

Hopefully this record will provide clues as to how the siblings Jean Mcnicol, John Mcnicol and Archibald Mcnicol lost their parents prior to adoption:
Father: George Mcnicol
Mother: Mary Sinclair, both of whom lived in Kilmaronock, Dumbarton, Scotland.

Here is some background information.
Jean Mcnicol born 1841 (Adopted maybe informally or formally?)

Historical account:
Lady Leith Buchanan"..lost her own daughter, when she was a child and when she heard of the Mcnicol children being left without parents, she took the little girl (Jean Mcnicol) into her home." Wrote Jean Bishop Robinson (nee Thompson)whom is Jean Mcnicol's granddaughter I believe.

I am not sure what happened to their parents and any assistance would be greatly appreciated. I know that Ross Priory is associated specifically with the Bucanan Clan and Lady Leith married a Bucanan. I believe Jean Mcnicol was taken in by "Lady Leith" Jemima Buchanan of Ross Priory, Scotland and husband Sir Alexander Leith Buchanan, whom married in 1830.

Jeans Birth: 13 Jun 1841 in Kilmaronock, Dunbarton, Scotland.
Death: ?
Married: John Bishop 20th Nov 1886

Jeans daughter: Mary Bishop, who married David J. Thompson in 1900.
Daughter: "Jean Bishop Robinson (Nee Thompson)"(Author of historical account, written Nov 26 1972 referenced above.

Brother of Jean Mcnicol: John McNicol "died at Dunsholt, Auchtermuchty (Spelling?) on 29th January 1913 in his 77th Year.

Brother of Jean Mcnicol: Archibald Mcnicol, 2nd Great Grandfather
Birth 4 Feb 1839 in Kilmaronock, Dumbarton, Scotland
Death 21 Feb 1910 in Ann Arbor City, Washtenaw, Michigan
Marriage to Helen Celest Treat 18 APR 1871 in Washtenaw County, Michigan
Fought in the Crimean War
1854-1855
55th Regiment
Arrival to the U.S. in 1866
1851 Scotland Census has Archibald at age 12 living as a boarder with John Burns age 68 and Janet Burns 62.
He is stated to be a scholar. So maybe by age 12 he had lost his parents therefore living as a boarder.

Take Care and I thank you in advance,

G20111