I too am interested in Thomas Falconer and Helen Simpson, their ancestors, and their descendants. I lean toward James Falconer and Melvil Millar as the parents of Thomas (m. Aug. 25, 1747), and James Simpson and Grissel Duncan as the parents of Helen Simpson.
Thomas and Helen had the following children as far as I know: Grizel (b. 1792), George (b. 1793), Thomas (b. 1794), William (b. 1796), John (b. 1798), Duncan (b. 1801), Christian (b. 1804), George Baird (b. 1806), Isabel (b. 1807).
Any more information or corrections on any of these people will be much appreciated.