Tried to follow this back to find original ... assume this might have been referring to Capt.Jock of Edinburgh City Guard who was lynched in 1736 & is buried in Greyfriars? If so, no brother James that I know of ... his father was Stephen (a tailor) & believe brothers named the same & Samuel plus a sister Rachel - little else known of any other relatives. The Porteous database (over 33,000 individuals) has a couple named James born right time - 1 in Midlothian.
1) James lawful son to William Porteous (f#11) & Agnes Foordie, Lasswade b 27 March 1696 Witnesses John Dickson & James Porteous (of Poltown Mill) ... this one may have died young as it appears they named another son James in 1713.
2) James b: 18/1/1697, s/o John Porteous bp: 24/1/1697 Culross Perthshire ... believe this is family #10 & wife/mother = Margaret DRYSDALE
We've got a couple of FALCONER spouses on file, but not the above couple you list - do you have date/place for the marriage?
Also, need to update URL previously posted as had to move the site a few months back http://porteousassociates.wordpress.com/