Margaret Skinner born in Kinnellar 1832 married Ronald Davidson 1 Jan 1852 (my gt Grandfather ) No point in expecting her marriage record to give the names of her parents, then, even if you could find it, as it's before 1855.
I would like to know who her parents were.
Margaret Ann Skinner or Davidson, aged 58, died in Aberdeen in 1889. Her death certificate should tell you who her parents were.
Ranald Davidson, aged 85, died in Aberdeen in 1912. His death certificate should tell you the names of his parents.
I see from the 1881 census that Ranald was born in Kirkmichael, Banffshire. There's a Catholic baptism in 1827 of Ronald, son of Peter Davidson and Isabel McGrigor. Tomintoul is in the parish of Kirkmichael, Banffshire.
There are also Catholic baptisms of several children of Ronald Davidson and Margaret Skinner in 'Blairs with Scalan':
George, born 26 July 1852
Ronald, born 24 January 1855
Isabella Anna, born 21 July 1860
Margaret, born 1 April 1862
Hector McLean, born 30 June 1864
Mary Jane, born 23 December 1867
Scalan is just over the hill from Tomintoul. It was a clandestine seminary for training Catholic priests during the 18th century. See
https://www.scalan.net/The laws against Catholicism were relaxed at the end of the 18th century, and the seminary moved to Blairs. See
https://www.blairsmuseum.com/College/history-college.htmThis all makes absolute sense because the children were born in Peterculter and Banchory-Devenick, close to Blairs.
I recommend getting the 1855 birth certificate because it will contain a lot of extra information that is not included in birth certificates in any other year.