Maria Katharina Schultz was born in July of 1767, just two weeks before the first census of Grimm, Russia, was taken. Her parents were Gottlieb Schultz and Sophia Annetta (Unknown) Schultz. In the 1775 census, she is identified as Maria Carolina, but her age shows that she is the same person as Maria Katharina in the 1767 census. The name Carolina is probably a census taker error. In 1798, she is identified as Maria Elisabeth Schultz Koch, and daughter Maria Katharina Schultz is a match in every way except name. It's possible that she was given three christian names at birth, Maria Katharina Elisabeth, and by 1798 she was simply using Maria Elisabeth in village records.
She is not named in the 1834 census, although her husband and children are. It's possible that she had passed away, even though her husband is not named as a widower. The most likely scenario is that she passed away before 1816, and her husband was identified as a widower in the interim, male-only census taken in 1816. Had she survived to 1834, she would have been 67 years old.
Pleve, Igor. Einwanderung in das Wolgagebiet 1764-1767, Band 2, Herausgegeben von Alfred Eisfeld under Mitarbeit von Sabine Eichwald, Published by the Nordost-Instsitut - 38085 Göttingen, 2005; page 76, family #26, Gottlieb Schultz family.
↑The 1775 and 1798 Census of the German Colony on the Volga, Lesnoy Karamysh, also known as Grimm; Published by the American Historical Society of Germans from Russia, Lincoln, NE, USA; Published 1995, family #110, Gottlieb Schultz family.
↑The 1775 and 1798 Census of the German Colony on the Volga, Lesnoy Karamysh, also known as Grimm; Published by the American Historical Society of Germans from Russia, Lincoln, Nebraska, USA; Published date: 1995; family #103 in the 1798 census, Johannes Koch family.
↑1834 Census of Grimm in the District of Saratov, Russia, dated 2 February 1835; Translated by Brent Mai, Concordia University, Portland, Oregon; Published by Dynasty Publishing, Beaverton, OR, USA; Published 2011; page 84, family #308, Johannes Koch family.