Family #78a in the 1767 Grimm census.
Family #28 in the 1798 Grimm census.
Family #153 in the 1775 Grimm census.
Katharina Schwarz was the daughter of Valentin Schwarz and a yet to be named mother. She and her younger brother Johann Valentin immigrated to Russia with their parents. Somewhere along the journey to the Volga River region, their parents died and the children were taken in by Heinrich and Katharina Heinz.
They are listed immediately following the Heinz family in the 1767 Grimm census: page 83 #78a, Johann Valentin Schwarz, 12, orphan, Lutheran from Lauterbach; Sister: Katharina, 15; Father: Valentin Schwarz; Lives with Heinrich Heinz. Also living with the Heinz family was Katharina's son from her first marriage, Wilhelm Klein.
1765 Grimm Census 
Also living with the couple but listed in a separate entry were two orphans: 
Katharina Schwartz is not listed by this name in the 1775 census. She was probably married and living in another household with her first husband. It's clear that she wasn't married to Kaspar Hepp yet, because he was still married to Maria Elisabeth at the time of the 1775 census. 
Katharina was 48 years old in 1798 and had two young children with Kaspar Hepp. She married Kaspar no later than 1790, and their first child was born in 1791.
1798 Grimm Census 
Her daughter, Anna Maria, married Heinrich Konrad Klein, the son of the young man she grew up with, Wilhelm Klein. The Kleins lived with Wilhelm Klein's mother and step-father Heinrich Heinz, and probably moved to Sarepta with his parents in 1788. This confirms that the Klein, Heinz, and Schwartz families stayed connected, even after the Klein's move to Sarepta and then back to Grimm.
Neither Katharina nor her husband Kaspar is named in the 1834 census, and it is likely that both were deceased.  Had Katharina survived, she would have been 84 years old.
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