Family #105 in the 1775 Grimm census.
Family #45 in the 1798 Grimm census.
1775 Grimm Census 
1798 Grimm Census for Heide Family 
Her name and age are a match for the wife of Johannes Schröder in 1798, but then she is listed in two families in the 1798 census. Additionally, her age is off by two years as Johannes Schröder's wife from her age in the 1775 census, but that is not uncommon. At 31, she would have been born in 1767, which is the birth year of her older sister Anna Dorothea. Anna Dorothea is not mentioned with her family in the 1798 census. Could this woman, the wife of Johannes Schröder, have been misidentified as her younger sister? The Schröder's entry in the 1798 census is listed below.
1798 Grimm Census Entry for Schröder Family 
If she is really Maria Katharina, it's possible she was listed in two 1798 census entries. She could have married between when her father's family information was taken and when the Schröder information was taken. There is enough of a gap between them in the census to make that plausible. [Family #45 vs. family #144.] Or she could have simply been in her parents' home when their census details were taken, and back with her husband and his family when those details were taken.
The problem is that there is no other Heide daughter with a similar first or second name that comes close to matching that data. Any 31-year-old daughter would have been listed in the 1775 census with her parents. The Heides had only two daughters: Anna Dorothea and Maria Katharina, born 1767 and 1769. Obviously only Maria Katharina would be a match for Johannes Schröder's wife, unless she was identified with the wrong name and she was really Anna Dorothea.
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