Good morning Mary
Found three children so far for William Reid/Jane Clark, all born @ Kincardine O'Neill (IGI) :
14/02/1858 - Isabella
09/01/1860 - Jane
29/08/1867 - James
Also couple were enumerated in 1861 census @ Craigley, Kincardine O'Neill with their two daughters :
He was aged 29 years, a ploughman, born Leochel and she was aged 31 years and born @ Kincardine O'Neill.
There were a couple of other Clark marriages about the same time @ Kincardine O'Neill....Helen Clark married Peter Lawson (1856) + Maria Clark married James Stewart (1862) but neither had Alexander Clark/Mary Duncan as parents.
Ysabeau