Scotlands People has an 1808 will and inventory for James Richmond, Major of Royal North British Dragoons, spouse of Janet Smith. Also a James Richmond/Janet Smith marriage at Loudoun in 1784.
Hmmm so who was the mother Mary in that 1801 baptism ? Or was that really a child of John and Maria ? That would make more sense, and there is a 4-year gap between the 1800 marriage and the first child listed on the army record.