I believe that Margaret was born in Stirling - marriage was in the Stirling Parish says 'both of this Parish'.
I'm trying to trace her parents; some trees on other sites say Margaret Buchanan Christie; I can't find evidence of this Buchanan name as yet.
Their children: William Reid 1782–1849 (my 4th Gt Grandfather)
John Reid 1784–1826
Elizabeth Reid 1787–
Alexandar Reid 1790–
Margaret Reid 1792
Gilfillian Reid 1798–1855