The first thing to do, assuming that she died in Scotland, is find Margaret's death certificate to make sure that you have the right parents. Did she marry? Because you can search the Scotland's People index for deaths of married women using both their maiden and their married surnames.
And if she married in Scotland after 1855, her marriage certificate will tell you the names of her parents and her husband's parents, including both mothers' maiden surnames.
Certificates are online at
www.scotlandspeople.gov.uk at modest cost.
I see that there is a family in Kennethmont in 1841 consisting of Robert Skinner, 45; Ann Skinner, 45; Mary Skinner, 15; Margaret Skinner, 8; Mary Taylor, 55; and William McLean, 20. Is this the 1841 census you are looking at? Robert Skinner and Ann Taylor had sons George, baptised 23 September 1819, and William, baptised 17 February 1821, both in Kinellar.
In 1851 James Skinner, 25, born Kinellar, is in Aberdeen with wife Jane/Jean Anderson, son James and George Skinner,
servant, 31, born Kinellar. I have not found George in 1861 or later. James and family are still in Aberdeen in 1861 and 1871 but I have not found them after that.
I have not found William in 1851.
