Unlike England and Wales a woman retains her Own/Maiden name upon Marriage.  It is usually as a matter of convenience that she takes her husbands Surname.  This is very useful when looking at gravestones as in England her married name is shown whereas, in Scotland, her Own/Maiden name is shown.  This is also to researchers advantage when searching the Scottish Statutory Death Records (on SP - ScotlandsPeople) as she is indexed under both her Married and her Own/Maiden Name.