She does not appear in either of the two Weber families recorded in the 1775 census. This may mean she was born in another colony. Another possibility is that her birth year is off by one year and she was born in 1775. If so, she may have been born after the census was taken, and that's why her name does not appear in the census.
Head of the Household Johann Heinrich Bleichroth, age 61
Wife [Katharina] Elisabeth [Weber] Bleichroth, age 60
Child #1 Johann Heinrich Bleichroth, age 19 in 1816, to Orlovskaya in 1823
Child #2 Johann Gottfried Bleichroth, age 26
Wife of Child #2 Sophia Bleichroth, age 24
Grandchild #1 Christian Bleichroth, age 3 years 6 months
Grandchild #2 Maria Margaretha Bleichroth, age 6 months
Child #3 Chistian Bleichroth, age 23
Wife of Child #3 Maria Elisabeth Bleichroth, age 22
Grandchild #2 Johann Christian Bleihroth, age 6 weeks
Elisabeth does not appear in the 1857 Grimm census.
It's very likely that she had passed away. If she were still living, she would have been about 81 years old.
↑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 #133 in the 1798 census.
↑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 86, family #313.
↑1857 Census of Grimm in the District of Saratov, Russia, dated 5 November 1857; Translated by Brent Mai, Concordia University, Portland, Oregon; Published by Dynasty Publishing, Beaverton, OR, USA; Published 2005.