| Father | Johann Christopher Fehr (1730 - 1815) |
| Mother | Maria Barbara Eichlin (1738 - 1805) |
| Sibling | Johannes George Fehr Sr. (1760 - 1847) |
| Sibling | Samuel Fehr (1772 - ) |
| Sibling | John Mathias Fair (1770 - 1866) |
| Sibling | John Henry "Johannes Heinrich" Fehr (1774 - 1861) |
| Sibling | John Christopher Fair Jr. (1769 - 1850) |
| Sibling | Anna Barbara Fehr (1768 - 1828) |
| Sibling | David Fair Sr. (1777 - 1862) |
| Sibling | Johann Henrich (Henry) Fair (1764 - 1794) |
| Sibling | Michael Fair Fehr (1778 - 1847) |
| Sibling | Anna Maria Fair (1762 - 1852) |
| Sibling | Elizabeth Fair (1759 - ) |