In biographies, Cornelia Friederica Christiana Goethe (1750-1777), turned “Cornelia Schosser” (marriage name, age 22), was the older sister, by 15-months, to Johann Wolfgang Goethe (1749-1832), founder of human chemistry (1796).
Overview
The following is a sketch of Cornelia Goethe, the sister of Johann Goethe: [1]

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References
1. Pecht, Friedrich, and Ramberg, Arthur. (1870). Goethe Gallery: Containing Characters from Goethe’s Works, drawn by Friederick Pecht and Arthur von Ramberg, fifty illustrations engraved on steel, with descriptive text by Frederick Pecht (The Councillor’s Lady Goethe, pgs. 24-29; Corneila Goethe, 32-35; Elective Affinities, pgs. 289-306). Appleton & Co.
External links
● Cornelia Schlosser (German → English) – Wikipedia.