Agnes was the daughter of unknown parents. The date and place of her birth have not been found.
Her husband was John McCreath, who she married on 21 NOV 1778 in Renfrew. Their nine known children were Robert (1779-1850), Helen (1781-?), Agnes (1783-?), John (1788-1849), James (1790-?), David (1792-?), Thomas (1794-?), William (1798-1874) and Matthew (1803-?).