| Grabenkamp, Heinrich Hermann | Helmers | 1891 | Bremen |
| Grabenkamp, Helene Margarethe | Helmers | 1901 | Bremen |
| Grabenkamp, Henriette Sophie | Helmers | 1903 | Bremen 1 |
| Grabenkamp, Johann Carl | Helmers | 1898 | Bremen |
| Grabenkamp, Johanne Dorothee | Helmers | 1889 | Bremen |
| Grabenkamp, Katharine Margarete | Helmers | 1905 | Bremen 1 |
| Grabenkamp, Richard Diedrich | Helmers | 1899 | Bremen |