| Father | Albert Fredrich Wilhelm Dettman (1849 - 1923) |
| Mother | Alma Ernestine Gruhle (1851 - 1939) |
| Sibling | Emma Bertha Wendel "Bertha" Dettman (1873 - 1956) |
| Sibling | Clara Emilie Dettman (1874 - 1960) |
| Sibling | Amalia Dettman (1875 - 1875) |
| Sibling | Hedwig Pauline "Hattie" Dettman (1876 - 1959) |
| Sibling | Ella Alma Dettman (1877 - 1952) |
| Sibling | Emil Oskar Dettman (1879 - 1973) |
| Sibling | Agnes Alwine Louise Dettman (1880 - 1968) |
| Sibling | Alma Auguste Dettmann (1881 - 1947) |
| Sibling | Robert John Dettmann (1883 - 1946) |
| Sibling | Wilhelm Max "Willie" Dettmann (1885 - 1967) |
| Sibling | Harry Dettman (1887 - ) |
| Sibling | Arthur Wigand Theodore "Wigand" Dettmannn (1888 - 1970) |
| Sibling | Albert Dettman (1890 - 1965) |
| Sibling | Viola Dettmann (1892 - 1959) |
| Sibling | Anson Dettmann (1893 - 1895) |