Widow Johanna Christina Brock is recorded on an appendix to the 1767 census of Katharinenstadt in Household No. 52 along with a note that she relocated to the colony of Wittmann in 1768.
The 1767 census records that Johanna Christina Brock came from the German region of Dresden.
There are no known surviving male lines of this Brock family among the Volga German colonies.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 2 (Göttingen: Göttinger Arbeitskreis, 2001): 332.