Family #124 in the 1798 Grimm census.
Family #201 in the 1834 Grimm census.
She passed away some time before 1814. By that same year, her widower husband remarried Katharina Elisabeth, last name probably Aab, the widow Mutz/Lutz. She is the only Katharina Elisabeth born near 1771, her approximate birth year as per the 1834 census.
Anna Maria Heimbuch Knoll's children are identified in the 1798 and 1834 census records as Jakob Knoll's children by his first wife.
Wife Katharina Elisabeth Knoll, age 63, second wife
Child #1 Johann Wilhelm Knoll, age 38 years 6 months, by first wife
Wife of Child #1 Louisa Margaretha Knoll, age 40
Grandchild #1 Philipp Knoll, age 20
Grandchild #2 Katharina Margaretha Knoll, age 17
Grandchild #3 Elisabeth Margaretha Knoll, age 13
Grandchild #4 Katharina Barbara Knoll, age 12
Grandchild #5 Anna Margaretha Knoll, age 10
Grandchild #6 Georg Jakob Knoll, age 6
Grandchild #7 Katharina Elisabeth Knoll, age 4
Grandchild #8 Johannes Knoll, age 1 year 6 months
Child #2 Georg Christoph Knoll, by first wife, age 8 in 1816, to household #286
Child #3 Johann Nikolaus Knoll, age 19, by second wife
↑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 #124 in the 1798 Grimm census, Jakob Nol/Knoll 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 61, family #201, line 2390, Johann Nikolaus Knoll, age 19, by second wife.