I have Elizabeth Marshall, b. 01 Jan 1794; d. 19 Jul 1890, both in Tullibody; m. James Allan, b. 20 Apr 1803 in Denny, Stirling; d. 11 Dec 1871 in Tullibody. Their daughter, Jane Allan, b. abt 1850; d 31 May 1905, both in Tullibody; m. John Dempster b. abt 1840 in St. Ninians, Stirling; d. 09 Nov 1914 in Cambus, Clackmannanshire.
Jane Allan and John Dempster are my great grandparents.
I don't seem to have your line of Marshalls on my tree.